I also do have a question regarding rexpaint:
the auto-wall feature does not really work with the extended unfortunately. Is this intentional?
I mostly place tiles by hand, or create some groups that can be copied around and later modified for variety, and also layers can help sometimes.
I'm very much used to working with Playscii and I really like its approach to UI and canvas navigation, but it doesn't feature auto-tiling in that manner. On the other hand, LDtk has all sorts of autotiling and custom rules, but isn't textmode-oriented (I did some improvisations with it by making copies of the charset in different color combinations though).
I'm always on the lookout for dedicated textmode editors!