sweeeeet - got the SCT programmer from Sean at HemiFeverTuning, loaded the 89 octane tune, which also included lockup engagement reprogrammed for 2500 rpm, and it does exactly that - I love it. Yah I know it's a small thing for $400, but now I can adjust all kinds of things and I can get more tunes, and I think I'm going to get one to set the lockup for 3000 rpm - I'm tempted to set it for 6k so it'll never come on. Plus if I choose to do a supercharger I'm now also set up to get tunes for that - bonus.
Lockup does still engage any time the overdrive is engaged even if it's under 2500 rpm so I'm asking Sean about that, but overall I'm really delighted that it works as I'd hoped. Also he programmed in a 91 octane tune which I'll try once I burn through the 89 in the tank now - should be lots more funerer.
Bottom line is it works, and I'll be leaving the RE right where it is