Syncro spark ignition control can be configured a few different ways..
TOTAL advance can be either 20 or 26 degrees, starting wherever you want..
TOTAL adance can occur at 4000 or 6000 rpm..No other options...
I know of no foreign made ignitions that can be user configured at all, except for where full advance occurs, usually at 28 or 30 degrees BTDC...
You have to be pretty critical to even tell the difference between ANY of these settings, except when starting the engine...Too much initial advance will get your hand slapped..
Pro Spark had an adjustable pot that could change the timing at WOT, I think they're not around any more...
Without a degree wheel and/or a dial indicator, you can't very well tell the difference of a few degrees either way anyhow...Try it and see[8D]