Old Fart, re your prop inertia on the 30, try fitting a heavier spinner. O/T trick to get the last miserly drop of fuel out of a Texaco engine. Dubro make a "heavy spinner" and if you have a lathe or a good mate you can get a set of "heavier" spinners made up to suite. My Texaco 30 has a slightly heavier spinner than normal and if I want I can get that 1800 idle using a wooden prop, but only just. With the airbleed carby, you aren't on your own, a lot of people have problems with them. I learnt a lot from the ASP engines I had in the 90's. With Texaco and you might like to try it yourself, close of the air bleed totally and play with the mixture, it works with the lower number (1A, to 4A) OS carbies.
New project, I am avoiding getting involved in (hah), 204 inch Lancaster with 4 x Saito 56 gas engines, and a similar B17. Should prove interesting. To those who have asked when I can suss it out I will post photos