There are timing differences in even some RCEXL models supplied as a OEM component.

For example the DLE 20 module has a #4 imprinted on the ignition module. This one has no advance curve. The advance suddenly changes at a lower rpm.

I would be careful about swapping between brands. You will need to check the resulting advance with a degree wheel..

Almost all ignitions fire the plugs at generally 28 degrees, full advance, before TDC at high speed but how they get there from the timing sensor is another story.

All the after market RCEXL ignitions have the same curve and only differ in how many coils or the type of spark plug connector.

Some brands have a retard algorithm and some an advance algorithm. Some brands sense at TDC and some at 28 degrees before TDC.

Some have Hall effect sensors and some have inductive pick ups.

On a RCEXL ignition, it fires the instant the magnet leaves the sensor. If you are measuring the advance and turn the crank backwards, you will get a wrong number like 40 degrees when it is actually 28 degrees when turning the crankshaft in the direction that the engine runs. The difference will basically be the width of the sensor plus the width of the magnet.

Milton Thompson has converted a lot of gas engines to RCEXL ignitions and he has to position the sensor to fire the ignition at, usually, 28 degrees before top dead center.