Pretty sad a bunch of neckbeards are crapping on this dude for asking a question. Speedrunning is a huge phenomenon that has alot of fans. Theres no "right" or "wrong" way to play Valheim. Its a single player (or small party) game, play however the ♥♥♥♥ you want. Anyone who thinks their opinion is important in how another should play a game is conceited as ♥♥♥♥ and possibly stupid to boot.

To answer your question OP, I've never tried. What would be the rules? Fresh world fresh toon? On my current world I could do it pretty quick (wont hazard a guess) because I have portals to every boss and I could easily put the summon loot on standby there. Interesting challenge at least.