I have a feeling your ignition issues are not related to having to be seated 005-009 primer depth, I think you have something else going on. I seat all my primers to where I can feel slight crush to bottom of pocket. With lapua brass srp that's usually 003-004 deep, alpha srp 001-002. Adg lrp 003-004. This is all I have ever done for prob 20k rounds of rifle fire. Only time I've ever not had primers ignite, was headspace issues caused by a deep chamber/too much shoulder bump upon sizing, or the primers were 40 years old and not stored well. My CDG 6bra, Alpha brass cci450 primers are 001 below case head, prob 600 rounds never once an issue. Other cdg 65cm with lapua seated 004 bout 500 rounds, no issues. As long as a primer is flush of the case head, you're good. Seating the primer deeper into the pocket past contact to the bottom of the pocket is not going to do anything for cocsistency of ignition. Benchrest guys do experiment with primer depth, but that's an accuracy thing.
Measure the shoulder with you bump too one brass you're having issues with and compare that with a deprimed fired case. If you're fire forming to an improved chamber (think 6br to dasher) you may need to set a false shoulder, or jam bullets into lands 10-15k to keep case head from coming forward upon firing pin contacting primer.