Hope it's permissible to add a couple to this excellent list (neither composer is, on a general Google search, extensively recorded, so trust this doesn't breach current YT rules on the Forum ?!):
Velislav Zaimov (Bulgaria): https://www.youtube.com/user/durchfuerung
Ryszard Bukowski (Poland) : https://www.youtube.com/channel/UCOjHd5dzUnpAHuDDsqAdjNA
One of the things I've learned from observing the posts on AMF over the years is that there's a dauntingly large number of composers from eastern Europe and the former Soviet Union states in general that have attracted the interest of members here. When faced with the prospect of investigating the music of these people, I've just wondered where to start and have, as a result, not started anywhere! Like any such daunting task (spring cleaning the house, for example) I guess the lesson is "it doesn't really matter where you start, as long as you start
somewhere". I'd hate to think there's some music out there that I'd really fall in love with if only I bumped into it!