In my experience, the problem with the dial back lights and multi-spark ignitions is...... They "seem" to be working fine, even when they aren't.
I've seen this happen on the dyno a few times where the owner of the motor being tested has brought his timing light with him.
Sometimes the dial back lights agree with the no dial back lights...... Sometimes they don't.
I've seen this play out several times.
No dial back lights and msd for me.
Exactly.
Ferret Instruments makes very good very bright timing lights. Guess who makes MSD , some Snapon and probably that blue light?
Shop for price. It varies a lot.
Personally I use a jegs branded flaming river light that I bought on sale for $25. It is not as bright as a good light but because it has no handle I can get it closer to the marks. It does not have dialback but so what, I don't trust them anyway. Almost all aftermarket dampeners are degreed and frankly a timing tape with bright yellow numbers on a black background works very well for me. Super glue both ends of the tape and it will never come off.