Some people could put in some time to good advantage learning about chicken genetics.
Rose comb comes from an inversion on chromosome 7 that flips one of the comb structure genes backward and at the same time whacks a large segment of a gene affecting sperm viability. The inversion is dominant meaning one copy is enough to show rose comb phenotype. The sperm viability gene results in sperm that can fertilize an egg lasting only 3 to 5 days where normally it would last 3 weeks or a tad more. There are two variants of the rose comb inversion, R1 and R2 where R1 affects the sperm motility gene and R2 restores the sperm motility gene while leaving the rose comb inversion. R2 is the most desirable variant since roosters have normal sperm viability. Unfortunately, the R2 variant has been found in very few chicken breeds.
Single comb/pea comb is on chromosome 1 and has a few known variants. Single comb is required to make a rose comb bird. You can't make rose comb without also having single comb on chromosome 1. As for stabilizing rose comb, that is simple to do. All it takes is making the right crosses to determine which roosters are homozygous for rose comb. Alternatively, a rose comb DNA test is being developed in Germany.
I've been working on blue egg laying Silver Laced Wyandottes since getting the first eggs in early 2014. Keith Bramwell was kind enough to provide eggs of his blue egg laying Brown Leghorns and I purchased some Silver Laced Wyandotte chicks from Jerry Foley. It has taken 9 years to get to the point where I have a few chicks that visually are silver laced and Wyandotte shaped and lay blue eggs. I have about 5 or 6 more chicks that so far look similar to the hen pictured. A few of them are rose comb. One more generation along with some DNA tests for the blue egg gene should be the tipping point where they breed true. Could I have achieved these results in less time? Yes, but I would have lost a few critical traits along the way. I want blue eggs, not tinted blue. I retained the zinc white gene for egg color which means my chickens will lay pure blue eggs that are not tinted by porphyrin.
https://pubmed.ncbi.nlm.nih.gov/8072931/