OK< MY 2 cents
I am NOT a fan of vests on dogs for upland game, and my reasons are this, over the yrs I have seen far too many vest end up causing more issue's and even injuries than one's without them
sticks and things get ram'd in under them, (one dog needed stitches from being jabbed when a stick got caught under it and it tried to push thru, far from no where a scary deal to see)
I have seen them get stuck to fences and in briar's too
so they seem to do both good and bad help at times
I personally won't use them unless in water hunting where they can help in both flotation and heat retention
the better advice I can offer is on long haired dogs, trim the hair under there arm pit's,
as this is where I see most get torn up from things sticking and balling up hair and such and eventually tearing the dogs up, or rubbing them raw, making it painful on them to keep going!
carrying a portable grooming kit helps here, also a first aid kit(never go on hunts without one in the truck and tend to carry certain items on me when I hunt with dogs any more!
basic grooming every day, and a good once over to find issue's both at end of day and randomly in the field , seems like a better plan than a vest
sorry if NOT want your asking for, just offering a different view to think about?
Safe hunting to you and your dog/'s