Purina QUIT making the pellet form of FR and don't even have it on their website anymore... as far as I know. TBH, I think the reason is they were having too much mold issues.
Adding water to make a mash can help avoid waste, for some people. I also don;t have MUCH waste issue... making sure feeders are raised to same level as the back.
Pass on Dumor feeds for me, too many reports of birds doing less than their best. But some people have acted satisfied.
I choose FR not only for my stags but also because I have chicks, broody's, and molting hens ALL the time. TBH... that whole calcium is bad for the roos thing... is A LOT of fear mongering. It's true that kidney failure or gout *can* happen. That doesn't mean it will. It is more likely for those who are genetically predisposed and very often overfed low quality treats. Many people have never fed anything but layer and have roosters living 8 years +!
No, I probably wouldn't feed a high protein greater than 20 ish % long term to layers... but it depends on their breed and the rest of their environment, free ranging changes things... AND 22% protein was shown to give the best hatch rates. But I would stay within 18-22% except during molt I *might* boost to 25-28% using game bird/turkey feed.
Regarding the ants... when I volunteered at a wildlife rehab... the locations where ants invaded... the feed dish sat inside another dish of water... like a mote. I also feel like I have seen they would not cross a Vaseline line??? I might make a bead of Vaseline around the base of the feeder... issue I see is dirt coating it quickly and no longer working IF it did in the first place. Odd, I never had ants go after chicken feed except watermelon and such. But I did watch them consume a dead rat this week! Ants are veracious... I would consider spraying near the ant source some permethrin or other fairly chicken safe product. Don't know if it is supposed to work against ants but it works for so many others I have a hard time thinking not.
I too can NOT get any fresher feed than you... and currently go through two 50# bags/week but only shop once per month. Make sure it is stored well on your end... THAT counts.
Good luck!