In the new launcher, I have two different Microsoft accounts.  Both of them are migrated so the login for Mojang does not work.  There is no add Microsoft button but there is an add Mojang account that does not work because I migrated.  My windows 10 version of Minecraft needs my dad's account for all the work and money I put on it.  My java version of Minecraft is on my account.  I can switch between both accounts because there is a switch accounts button but that takes time and when I was playing on java before and I want to then play windows 10 I have to close java.  Then I have to open the launcher.  Next I have to switch accounts and close java.  Finally I can play on Minecraft windows 10 version.  I can do this process but it takes time.  If Mojang can just add something to have my dad's account to just be for windows 10 and my account just be for java, that would be very helpful.