I know this is not popular but changing your sequence settings to animation codec will give much better quality compared to ProRes422 with graphics.
But you will have to render all and loose realtime performance.
Apple is NOT going to bring us a iMovie Pro.
Sure, they love selling iPads.
But they also like selling MacPro’s.
Apple isn’t that stupid to hijack the Supermeet and present a consumer app , when Blackmagic has released a Thunderbolt Pro i/o in the same week.