Actually, this isn't spoilers anymore. The game's been out for 6 months now to the point where lots of people have already completed it, and so the plot is pretty much well-known right now, including the new bosses and the plot twists.
Anyway, I'm gonna admit that I'm actually a little rusty on wormhole riding. The last time I did it was around Christmas last year to clean out the last hole that I had to get a legendary from, with which case it was Landorus. After that, I basically didn't touch the wormholes anymore because I got what I needed, including the UBs, with their correct nature. As for the minigame itself, the controls are pretty stiff to start off with and I had trouble trying to steer Solgaleo at speed, so I kept crashing into electricity orbs and as a result falling into a hole I really didn't want to be in. As for shiny hunting, I'm not really interested in doing it, especially considering I've gotten a lot of wormhole shinies over Wonder Trade.