I layed mine out in the sun so it would flatten out some, good side up so the backside didn't collect any condensation.
When I installed it, I only put a few splashes of seam sealer in the center area, just to hold down, then ran it up the walls cutting out around the studs and stapled it.
I didn't shape it around the sill , I made gradual curves if you know what I mean.
I wasn't going to be walking around in there, I did it that way so it was easy to clean...no sharp corners or edges for poop to collect.
If I had sheet rocked or covered walls, I would have done the same thing,
No corners for poop to collect and build up.
Twice a year I do a complete clean up, just sweep everything out....very little scraping with the broom.
If I ever want to replace it, just pull the few staples out and pull the hole flooring out in one piece or two pieces!
If you glue, nail or staple the heck out of it it will be a real chore to remove it!
I do the same in the laundry rooms of my rental units, which gets replaced about every three years, (remove the old flooring of course) ruff cut to size the vynil, remove the half round molding, put thin beads of sealer down, (not flooring adhesize) lay the flooring down, use a flooring roller to squeze the sealer down and make it flat as possible, trim to size using the wall as an edge, then re-instal the trim.
From start to finish I can do a 10x12 laundry room in less than hour.
Minimal scraping, the hardest part is not breaking the trim.