Thanks!Sure! Just exit the game and return to the Mii Maker app, and Loadiine should boot again.

I have the same setup as you and never once had a crash after playing a game and going back into miimaker and loading another game. So I can only think something is wrong with your setupYeah, but then the Wii U crashes when loading the next game (5.5.1 PAL-User here).
It's much better to turn your Wii U off and on again to play the next game. Those 20-30 seconds more are worth it to have everything working fine.