I started those later "BYOGear" fields so I could use my own stuff, so I understand the rental-only apprehension. Although there's no reason the two models couldn't be combined. In fact the only key aspect was that renters were isolated and hourly field fee is the only pricing control.
Simply start with the rental only model and isolate "Renters" and "advanced" players. Renters can opt to play with these advanced players, but never the other way around. Limited consumables still applies. There's no reason you couldn't setup a different 'practice' pricing structure for tourney players either.
So you have your own gear, show up to find only renters. Toss your stuff in the car and play an hour or two of rental. Enough people with gear show up so you can use your stuff. You convince them to allow you and your buddy to play with the gear you brought.. essentially making them play BYOG.. or they want to play in larger groups... Either way, you're paying the same hourly rate and the field owner is making the same income.
This happened frequently when we transitioned from pump to semi. A small number of repeat customers wanted to play with their new guns. We simply asked the renters and if the teams were balanced they were typically all for it. Funny side effect was that those semi guns got passed around based on who had paint, really boosted camaraderie. The kid who hid behind bunkers all day was suddenly Rambo for twenty glorious minutes.
Regarding paint consumption... It was fascinating for us to observe players automatically compensating for the paint rations. We also allowed dead players to leave their paint AND gear back at their starting point. This feature alone was huge. It caused automatic game regulation so each game was always close and rarely ever ended from full elimination.