As someone who dual boots currently, performance is pretty much on par with SteamOS. Performance is not an issue.

Also, the current dual boot setup process is literally exactly the same as on any other laptop or desktop. Sort out partitions, startup to BIOS, boot to installation media, install. Literally no workarounds involved, it’s a bog standard standard dual boot process.

But baked in partition resizing and bootloader for easier switching would certainly make the whole process easier.