If it helps, I just set up my 451's distributor for a lot of advance on startup (but not quite full), then advancing gradually to max.
One superlight (Mr. Gasket 925B) spring for the low-rpm advance, then an OEM spring with a loop.
The loop engages at the idle rpm and its spring dominates thereafter.
So there's about 14 at crank (no kickback), 27 idling, 35 at 4000 and max of 38 less box retard at the high end
The trick is in finding the right loop length. I got lucky.

They are totally adjustable and a really nice unit. I have it set up now for 20 initial and 16 in the dist. The cam is a 254/.520 and it just seems the idle has always "wondered". I have the option with that unit to lock it out but just thinking if there is a light spring that works that someone has already experimented with I would ask the question. My next move is to try locking it out and work back form there.

I use the Mr. Gasket 925B distributor springs in a lot of different brand distributors, maybe they will work for you also
They have work good in all the after market replacement Mopar distributors I've use them in