To allow .46's, with or without .015 or .018 lines, would be be unfair to everyone who has invested time and money into 40-powered stunters.
A rule is a rule and we have to draw a line somewhere.
If you want of go "over-40" just fly AMA or FAI Stunt. P40 was created so some of us could fly stunt with buying 75's or electric motors and $2,000 worth of batteries.
If money is not object, there are a world of events to buy.
Well, gee, I thought the idea was to get folks flying Stunt. 'Scuse me! If a guy has a Mo'Best, Pathfinder, Cardinal, Berserker, or Col. Tom's P-51 (recent SN), with a .40+ , I'd like to let them fly. It doesn't make a .35 or .40 powered model non-competitive. If you think so, ask the Ozzies about some bloke with a Heartbeat Models profile Sukhoi who won their NATS...what...TWICE with it! OS .40FP powered!
Lots of us are getting older and retiring, some (not me) actually have a decent retirement income and can travel around the country and fly in contests all over. Wouldn't it be nice if all the rules were the same, I ask? Most areas of the country don't use displacement rules, just fly Profile Stunt. They don't regret their decision to lose the restrictions, and just let 'em fly. I like it.
Uhhhh...you thought that .46's would be using .015's because of this being "P.40 Revised Edition"? Just like you'd be using .015's on your .21FP powered Flite Streak, because, you're flying it in P.40?! C'mon...that's just stoopid. You have to ref the AMA line size and pull test regs. Easy enough, that's the way to write these non-AMA events, to protect yourself from liability problems. If somebody thinks .46's should use .015's, they should submit a rule change proposal. Our man Dave Gardner managed to get the lines changed to .012's for .25's, without a major fist fight. Great idea!
The #1 REASON that I proposed the NW P.40 event be changed to Profile Stunt, with the same power rules as PA: Dummies keep writing it as "P-40". It's not for Curtiss Warhawks, tho it's ok, if one insists...

Steve