For any users in the future, just couple things I came across that might be helpful.
---------------------------------------------------- Sometimes .txt files in Linux do not contain an extension in the filename, the following line will allow you to use this script with those files (remember to add coma at the end of this line if in the middle of your template list). `{"", "", "######################################"}`
---------------------------------------------------- The original script adds separator to the above line where the cursor is located. If for whatever reason you would like the separator to be added to the line below the cursor you can change `iCurPos = geany.scintilla("SCI_POSITIONFROMLINE", iL - 1)` to `iCurPos = geany.scintilla("SCI_POSITIONFROMLINE", iL - 0)` which seems to work. I always like to know little tweaks like this just in case certain situations benefit from one or the other.
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Anyways, hopefully this will be helpful to someone someday.