diff --git a/external/timemory b/external/timemory
index 6baee4c8d9..1f4e7602a4 160000
--- a/external/timemory
+++ b/external/timemory
@@ -1 +1 @@
-Subproject commit 6baee4c8d9201d748b50a44ec2116f73afa80883
+Subproject commit 1f4e7602a404ffb18998c5a1c0268de989df2d92
diff --git a/source/bin/omnitrace-avail/generate_config.cpp b/source/bin/omnitrace-avail/generate_config.cpp
index a07a528107..ea5b7f9103 100644
--- a/source/bin/omnitrace-avail/generate_config.cpp
+++ b/source/bin/omnitrace-avail/generate_config.cpp
@@ -82,6 +82,10 @@ ignore_setting(const Tp& _v)
        category_view.count("settings::deprecated") == 0 &&
        _v->get_categories().count("deprecated") > 0)
         return true;
+    if(category_view.count("advanced") == 0 &&
+       category_view.count("settings::advanced") == 0 &&
+       _v->get_categories().count("advanced") > 0)
+        return true;
     return false;
 }
 }  // namespace
@@ -175,7 +179,8 @@ void pop(type_list<Tp...>)
             type_list<std::string>{}));
 }
 
-void update_choices(std::shared_ptr<settings>);
+void
+update_choices(const std::shared_ptr<settings>&);
 
 void
 generate_config(std::string _config_file, const std::set<std::string>& _config_fmts,
@@ -406,7 +411,7 @@ generate_config(std::string _config_file, const std::set<std::string>& _config_f
         _open(ofs, _fname, "text")
             << "# auto-generated by omnitrace-avail (version " << OMNITRACE_VERSION_STRING
             << ") on " << tim::get_local_datetime("%F @ %H:%M", &_time) << "\n\n"
-            << _ss.str() << "\n";
+            << _ss.str();
     }
 
     // restores the original serializer
@@ -416,7 +421,7 @@ generate_config(std::string _config_file, const std::set<std::string>& _config_f
 }
 
 void
-update_choices(std::shared_ptr<settings> _settings)
+update_choices(const std::shared_ptr<settings>& _settings)
 {
     std::vector<info_type> _info = get_component_info<TIMEMORY_NATIVE_COMPONENTS_END>();
 
diff --git a/source/lib/common/join.hpp b/source/lib/common/join.hpp
index cd2c7942e3..de1e5d055b 100644
--- a/source/lib/common/join.hpp
+++ b/source/lib/common/join.hpp
@@ -79,16 +79,22 @@ template <typename DelimT, typename... Args>
 auto
 join(DelimT&& _delim, Args&&... _args)
 {
+    using delim_type = std::remove_cv_t<std::remove_reference_t<DelimT>>;
+
     std::stringstream _ss{};
     _ss << std::boolalpha;
-    OMNITRACE_FOLD_EXPRESSION(_ss << _delim << _args);
-    auto _ret = _ss.str();
-    if constexpr(std::is_same<DelimT, char>::value)
+
+    if constexpr(std::is_same<delim_type, char>::value)
     {
+        const char _delim_c[2] = { _delim, '\0' };
+        OMNITRACE_FOLD_EXPRESSION(_ss << _delim_c << _args);
+        auto _ret = _ss.str();
         return (_ret.length() > 1) ? _ret.substr(1) : std::string{};
     }
     else
     {
+        OMNITRACE_FOLD_EXPRESSION(_ss << _delim << _args);
+        auto   _ret = _ss.str();
         auto&& _len = std::string{ _delim }.length();
         return (_ret.length() > _len) ? _ret.substr(_len) : std::string{};
     }
@@ -101,16 +107,22 @@ template <typename DelimT, typename... Args>
 auto
 join(QuoteStrings&&, DelimT&& _delim, Args&&... _args)
 {
+    using delim_type = std::remove_cv_t<std::remove_reference_t<DelimT>>;
+
     std::stringstream _ss{};
     _ss << std::boolalpha;
-    OMNITRACE_FOLD_EXPRESSION(_ss << _delim << as_string(_args));
-    auto _ret = _ss.str();
-    if constexpr(std::is_same<DelimT, char>::value)
+
+    if constexpr(std::is_same<delim_type, char>::value)
     {
+        const char _delim_c[2] = { _delim, '\0' };
+        OMNITRACE_FOLD_EXPRESSION(_ss << _delim_c << as_string(_args));
+        auto _ret = _ss.str();
         return (_ret.length() > 1) ? _ret.substr(1) : std::string{};
     }
     else
     {
+        OMNITRACE_FOLD_EXPRESSION(_ss << _delim << as_string(_args));
+        auto   _ret = _ss.str();
         auto&& _len = std::string{ _delim }.length();
         return (_ret.length() > _len) ? _ret.substr(_len) : std::string{};
     }
diff --git a/source/lib/omnitrace/library/components/backtrace.cpp b/source/lib/omnitrace/library/components/backtrace.cpp
index a870ae6f64..e1b3c2a312 100644
--- a/source/lib/omnitrace/library/components/backtrace.cpp
+++ b/source/lib/omnitrace/library/components/backtrace.cpp
@@ -425,7 +425,6 @@ backtrace::configure(bool _setup, int64_t _tid)
         }
 
         _sampler->stop();
-        _sampler->swap_data();
         if constexpr(tim::trait::is_available<hw_counters>::value)
         {
             if(_tid == threading::get_id())
@@ -653,27 +652,29 @@ backtrace::post_process(int64_t _tid)
                                  "end_ns", _end_ns);
     };
 
-    auto _raw_data = _sampler->get_allocator().get_data();
+    _sampler->stop();
+    auto _raw_data = _sampler->get_data();
+    OMNITRACE_CI_THROW(
+        _sampler->get_sample_count() != _raw_data.size(),
+        "Error! sampler recorded %zu samples but %zu samples were returned\n",
+        _sampler->get_sample_count(), _raw_data.size());
     // single sample that is useless (backtrace to unblocking signals)
     if(_raw_data.size() == 1 && _raw_data.front().size() <= 1) _raw_data.clear();
 
     std::vector<sampling::bundle_t*> _data{};
-    for(auto& ditr : _raw_data)
+    for(auto& itr : _raw_data)
     {
-        _data.reserve(_data.size() + ditr.size());
-        for(auto& ritr : ditr)
+        _data.reserve(_data.size() + itr.size());
+        auto* _bt = itr.get<backtrace>();
+        if(!_bt)
         {
-            auto* _bt = ritr.get<backtrace>();
-            if(!_bt)
-            {
-                OMNITRACE_PRINT(
-                    "Warning! Nullptr to backtrace instance for thread %lu...\n", _tid);
-                continue;
-            }
-            if(_bt->empty()) continue;
-            if(!pthread_create_gotcha::is_valid_execution_time(_tid, _bt->m_ts)) continue;
-            _data.emplace_back(&ritr);
+            OMNITRACE_PRINT("Warning! Nullptr to backtrace instance for thread %lu...\n",
+                            _tid);
+            continue;
         }
+        if(_bt->empty()) continue;
+        if(!pthread_create_gotcha::is_valid_execution_time(_tid, _bt->m_ts)) continue;
+        _data.emplace_back(&itr);
     }
 
     if(_data.empty()) return;