Is it a red setter or irish? Not the same thing. I don't know enough about good field bred Irish to speak to them but I don't believe good red or red and white setters are slower than setters in general to develop. Unless you mean they are hell on wheels and bowl over birds for awhile before figuring it out....
Assuming it came from a reputable breeder, I might check with them about how they usually bring their dogs along.
I have become a believer in starting stop to flush training right along with whoa training, it really helps with this issue.
Thing is at this time, you are in hunting season. Choices are to stop hunting and focus on training or keep hunting.
I think the majority of folks would keep hunting.
Whether to shoot or not depends on the dog. Sounds to me like it is busting birds and enjoying it. Nothing wrong with that at this age, but I'd probably avoid shooting birds in that case, and focus on finding an opportunity where it points or pauses a bit to shoot. Especially if you think it's smelling birds it can't see initially and still busting in on them. If it's inclined to point a bird it can smell but not see once in awhile, I'd work to find places where the cover was thick enough to set up such situations.
I might shoot birds that I flush in your situation, depends on the dog. I might also whoa the dog (if it knows that command and responds to it well in the field) move in to likely looking spot, reach in the vest and toss a bird, then shoot. Sometimes handling a bird can do wonders for them, sometimes it doesn't move them along any faster. Have to know your dog.
If the dog is having fun, finding birds, but you aren't getting many shooting opportunities because it is busting them, I'd just keep it up for now and make a plan to start training next spring, assuming it's ready. Again I'd check with the breeder on timing of development of their dogs. I'd be disappointed if one of my GSP's wasn't hunting with a mimimal level of proficiency at 7-8 months, but with most setters I'd probably set my sights on being at the same stage a year or two later.