So you put "super light" springs in so the timing is all in at 1500. How much time does your drag race engine spend below 1500, or 2500 even?

Big cam, little vacuum, engine idles down, timing comes out and slows the engine, Now more timing comes out. Now it shuts off in gear unless you keep you foot on the gas or crank the idle screw in. Now you've upset the throttle blade to transfer slot relationship.

I know, let's make the total curve real short so the timing doesn't fall back 25 or 30 degrees at idle. Let's make it 10, or less.

Why bother. Lock it out. You can always put springs back in, if you don't like it, But you won't.

I have never seen anyone set the timing at "whatever the highest RPM the engine sees". Usually, unless they have to rev the guts out of it to get the thing totaled out with 3 or 4000 RPM springs in it, it gets set at idle. Pro Stock, fuel cars, Comp, Super Stock, Billy Bracketracer, doesn't matter.

Typically, distributors are locked, just like a crank trigger. Most people who can use a crank trigger, do. Some can't. Timing is set to the max desired. Ignitions, Grids, boxes and gizmos are used to retard the timing from that point, for whatever reason there is to retard it. Start, manage the tire early, nitrous, top end speed, traction control, whatever,