Google search revealed quite a few threads about what value the main spark table values mean in relation to actual crank value.

I don't know why I am having such a hard time understanding this, but maybe once I get it, life might be easier.

In any case, in my other thread about some data logs and the main spark table, using a 747 ecm and a modified ASDU bin, with the latest 747 adx and xdf's I am in fact seeing a matching value between the crank and the spark table.

Now there is a reply from EagleMark about this in this linked thread

Quote Originally Posted by EagleMark View Post
In $42 there is no correction for main/warm spark bias in spark advance table, what you see is spark advance plus main spark bias. So comparing to data it all off by main spark bias as it's supposed to be. What you need to know is if distributor is set to zero, does timing at crank match data? If so spark table should be off by main/warm bias. 350 and V6 have a bias, BB/454 does not.

I fixed it in next release. You will see actual in SB or BB.
If I am reading the above in yellow correctly, then if my spark table shows a particular cell at 21 degrees, then the crank reading should be that cell plus the value 9.84 degrees for spark bias for a total of 30 degrees?

If I am reading the above in red correctly about the "next release", then the main spark table reading will match the ignition analyzer crank reading regardless of the spark bias due to the fact that the adx/xdf was written to compensate for the spark bias value as long as the initial timing value of the bin matches the actual physical timing value of the distributor.