This is a very good idea and it does not only make sense when you have multiple instances open. Probably a low percentage of Renoise users have multiple versions open in many circumstances, equally so, probably just a low percentage uses 32bit and 64bit versions (and has VST bridge issues) exchanged in such quickness that he/she can’t just pop up the about dialog. So what. Don’t just annoy the topic. I’ve posted just a week ago about this same thing and I don’t think I ever ran 2 renoises atst. See here. It’s always handy to know which file you’re working on and you already know you’re working in renoise because of the icon. 32/64 info could be in the icon.
Filename/song title first: Firefox does it (current tab title). Gimp does it. VLC does it. Notepad does it. It’s the right thing to do.