[Tkinter] Treeview expand button size

[Larz60+]

Now, this is an experiment. Set all columns of the treeview's stretch attribute to true
this may set the horizontal stretch, but won't help with vertical stretch. (one of the reasons I say tkinter's geometry su...
(Shipman page 141)
Don't know if it will work or not, but worth a try.

see this perhaps? https://stackoverflow.com/a/48065335