After reading around, I've found people saying that BYOND should be able to display Cyrillic characters without problems for Windows 10 if you have the language pack installed. However, I've had the Russian language pack installed for ages and have used it without any problems, yet when I load into any servers with Cyrillic characters, they're incomprehensible garbage. Does anyone know how to fix this?
I'm not sure how to fix this in 512 or earlier, but just to let you know, version 513 should be much friendlier to Cyrillic.