I also, would opt for the bushed version...weight...and my experience with several .35 5224s over 40 years old and not anywhere near worn out
In fact one always was fairly low on power and hot nose, so I chucked up the crank and progressively polished it with finer and finer diamond grits --- I doubt I ever did reduce the crank diameter ----but that engine now has well over 4 gallons of fuel through it and you would think it still new
I suppose I could have lapped the crank to the bushing.... but unsure of the best method, I just super polished the crank.... and let the rest of the engine break in over time.... and believe me ALL Enya's take a goodly bit of seasoning to be fully broken in!
If the new beautiful red head Old skool .35 was not so expensive I would have one
Back to the Ring master S-1... even a porky one..... the Bushed 30 is probaly a good fit (IMO) while a good broken in Enya BB 30 would have much more Umph than needed---- and require unnecessary tail weight to haul around