I'm not dealing with OEM spec engines much. An engine that operates primarily at part throttle from idle to 3000 RPM is a different animal from a race deal that's either on or off. Or even a race deal with tags that idles around on the street some on a Saturday night.

Big, lumpy cam = >240*-245* @ .050. <10" vacuum. Usually a roller of some type.

An electronic means of retarding timing when starting, high gear retards, pulling timing at the hit on a big power, suck track deal, are all great ideas to be able to do. But some of us are doing the KISS with just a 7AL with a crank trigger and a carb deal. So basically I don't need a curve. Also, race cars should have separate start and ignition switches to be able to spin the engine with the ignition off anyway. Easy to do, even if you're still using a stock ignition switch.

Having the thing fall back 15* or 20* from total timing usually ends up making you open the carb to make it idle. Now you've upset the throttle blade/transfer slot relationship or drilled holes in the blades. Either way, you're doing stuff to the carb you wouldn't have if it had the timing in it. I typically set the throttle/transfer slot relationship by eye, install the carb and keep my fingers off the idle speed screws for all but fine adjustments. If it won't idle, I fix the reason for it. Maybe a little air bleed somewhere.

Big roller, 800 RPM in gear without having my foot on the gas. Plugs a little hotter than most run, Sit and idle like that all day if I want.