Versatune allows for tuning up to like 8k right? Where does the AP stop at?
Yes, by default it allows you to tune up to the maximum values embedded into the ECU. But since a few years it allows you to override these values and I think the limit of the maximum values. By example you can tune past 4BAR of boost, past load 4, past 8k rpm, and so on.
When they launched this feature I remember them saying that at least for load and RPM which a lot of tables are scaled for, these tables will be rescaled at a lower resolution by increasing the step in the last part of the table: by example for a load based table, instead of having the load step increased with 0.125 between load 2 and load 4 in those tables, it will to go, say, 0.150. This is needed for the tables to require the same size in the ECU memory.
Of course you can't increase these limits for voltages which is enforced by how sensors work (say, MAF voltage from 5 to 6V or something), or if a number is held internally on 8 bits to go to values that need 16 (or 9) because of how these values are written in the ECU memory location, but increasing absolute RPM from 8 to 10K should not be a problem.
Better contact them if this seems to be a possible solution for you. If it works the way you want it may be a lot cheaper than going stand-alone.
Where does the AP stop at?
I thinkthe AP stops at 7k and will interpolate the table/curve/whatever based on the shape of the curve/table. This is what it does with the load tables, ignition tables and everything, past 7k.