This is a pic of the slide from Mernickle Custom Leather. It can be had in .357 or .45 size and the loops are made of heavy elastic - they hold your reloads securely but it's not difficult to pull one out as needed. Rarely does a shooter need more than one reload for a stage, and even then that's rare. This slide can be moved from belt to belt and if you get one for each caliber you can swap them out as needed if you shoot multiple calibers. You can also position the slide on either strong or weak hand side of the belt, or wear your buckle in the back and place the slide between your holsters.
I'm also a fan of their shotgun belt - same type of loops.
And their Gunfighter Series holsters. Metal lined to hold the shape and not let the holster collapse after the draw. The High Performance Series is also metal lined and just slightly different on the cant and drop IIRC.
Mernickle (as most custom leather makers) does have a wait list. If this is the direction you want to go, or any cutom leather maker for that matter, try to find someone with an extra set of leather to let you borrow until your order arrives. This will also let you experience different holsters and determine what you want long term.