@jeremiaskleer its the normal policy of Geany to not accept hand edits to `geany.glade` because they tend to cause Glade to make many unrelated changes the next time its used. One of the Geany contributors even made changes to Glade to minimise the changes it makes, but that only works when its reading a file it wrote IIUC.
And yes I _totally_ agree with you about needing to compile your own Glade 3.8.5 or 3.8.6, I won't either, but until support for GTK2 is removed from Geany, the Glade version can't be advanced to one thats available in repositories.
But since the functionality is available in the "autoclose" plugin there may not be much incentive to add this, but lets see if anybody tests it and reports its working.
I tried compiling glade 3.8.6 with no success within 1 hour. I stopped. Maybe someone already having glade in correct version could help.
I don't agree with the last point: I see no reason for not fixing a feature in Geany, in my opinion not usable, because it can be circumvented with a plugin, although there is a easy fix, already prepared. Of course I am biased as I invested hours in understanding, fixing, and preparing a fix. I love Geany, I use it in on every computer I run. I circumvent enterprise firewalls and software policies just to install Geany to use it everyday. For a while I was compiling and preparing ubuntu-packages and providing them in a repository when Geany in the official repositories where behind the current development.