Perhaps I'm missing something here, but I just installed pluma
on my Fedora (Rawhide) system, and the "default" save action for a new file was to present a list of "Recently used" directories from which to select, and, if none is selected, an error is popped telling you to select a directory.
is started with a file name, the default action is to save it in the directory from whence it was loaded.
$ cd tmp
awk bash C ECR go high low lucian moz_cookies.rkl.rep sqlite.rkl t1
$ pluma Tmp
awk bash C ECR go high low lucian moz_cookies.rkl.rep sqlite.rkl t1 Tmp
$ pluma --version
pluma - Version 1.8.0
Note that, since I happened to be on my Rawhide system, the version I'm using may not be the one in your Mate.
I slight "bug" I noticed when I started pluma
with no file name was that it displayed the location to which the file was saved as ~/Tmp
while saving it in ~/tmp/Tmp
Except for the presentation of the "Recently used" directories (which is, IMHO, a "nice to have" feature), the file saving actions and options of pluma
are, again IMHO, quite "vanilla."