Tufts is still my home turf. As for “postfix diacriticals,” I’m still sorting that out, but the two systems are close. Anyway, Hugh, The ease with which you toss terms like that about makes me all the happier to have you in my corner. Thanks for the help.
In Ubuntu I use the Greek polytonic keyboard input, and select a hotkey for switching. I use vim, not emacs, so I have a bunch of statements like “map α a” in my .vimrc to make edit mode work in Greek keyboard mode. I switch a lot between Mac/Windows/Linux, and am happy enough with prefix. I do wish that there was a standardized keyboard between Mac/Windows/Linux. The subtle differences mean that I can only type fast on a Mac. (Though not perfect, Mac’s polytonic Greek keyboard is the best thought out of the three I use.)
The biggest issue that I have run into, dealing with different input methods, is that there are differences in encoding for pre-composed versus combining character versions of some of the glyphs, and this can make searching for text non-functional, especially when it’s using exact diacritical match rather than fuzzy.