About the Ryobi 4stroke oiling system, yes they've always had a wet-sump system with baffles such that adequate lubrication is maintained regardless of engine orientation. The gen I 26cc with metal "oilpan" reported had a problem with the baffling and didn't work well inverted. The later gen II with plastic oilpan and the Pro-grade gen III are supposedly worthy of the 360deg orientation claim.

I believe the gen III is quite a bit lighter weight than the gen I & II, though I don't have first hand knowledge since I've yet to take apart mine to see. Please let me know what you find out. I'm very interested.