Spawn rate seems the same as snape grass, there are multiple 2 spawns if you make your way around the swamp you should always have some to collect. I do however support any QOL's for Ironman.
The spawn time isn't slow I can do a lap and when I'm back at point A they have respawned there is no wait. So I'm unsure if you're just waiting at the same spot?
Not exactly sure what the respawn timer is, but it definitely does seem like it takes long to respawn when I was picking them when I was an Iron Man. I support.