What's the footprint measurement of a 10g long? Can check the footprint needed for the different pleco species on seriously fish.
I usually wouldn't recommend less than a 15-20g for a pleco, even a small one like a bristlenose. But if the tank is longer than average, and the keeper is experienced and willing to maintain the water quality and be very careful (as I know you are), then it might just be do-able.
If the footprint is big enough, you need to bear in mind that even the smaller plecos - Bristlenose, rubberlip etc, are poop machines, so have a heavy bioload. And once you've added substrate/hardscape/decor etc, that you'll have a bit less than ten gallons of water total. So you'd want to stock the rest of the tank very lightly, and be very on top of water tests and water changes, and likely be willing to upgrade the tank if it becomes too hard to maintain, or if the pleco seems to be too big for it visually.