I'm the maintainer of MultiMC (https://multimc.org) - it's a third party Minecraft launcher. Because pretty much every GPU driver special cases Minecraft, I'd like that same special case to apply to MultiMC.
Basically, a Java process started by 'Minecraft.exe' will use the discrete GPU and will get some optimizations. Same should happen for Java processes started by 'MultiMC.exe'.
I get questions from users about this quite regularly, and because Minecraft is treated as a special case by everyone, the only workaround is to trigger the discrete GPU when Java is used, or to rename the executable. As you can imagine, it can be used - and often is - for many different reasons which do not involve 3D graphics, effectively draining laptop batteries and burning power for no reason.
It is a constant issue, for many years now. And answering the same questions from users all the time is getting old.