I find the described throttle barrel issues interesting 🤔 Thousands of flights from the 140 to the 200 and I've never had fuel leak from, or any running issues attributed to the barrel. Apart of course from an incorrectly machined one I had ages ago.
As such, I can't really see adding extra O rings to be a benefit. Maybe it does? However I'm not going to modify anything unless absolutely needed. Until then, keep on keeping on 😬

PS. Rapicon - 9% oil, 33% nitro 👌💪😃