Anyone have any idea whether the E38 (etc) simply switches from cell to cell on table lookups, or interpolates between two cells?

I understand that the ECM interpolates between the high and low octane tables based on the octane scaler, but on a regular table, for example the knock sensor sensitivity calibration (cyls A thru H) does it simply look up one cell until it gets to a switch point between two cells, like @ the 50% point on rpm/airflow axis?

Question arises out of the newer supercharger calibrations (LS9/LSA) where the 200mg and 300mg cell columns have been dropped to give two more columns to support the higher airflows up to 1300mg vs 900mg.

When looking for a number where these columns are missing at the lower airflows, does the ECM simply swap cells when it gets half way between 100mg and 400mg airflow number? At 250mg? For example .

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Or work out the required number based on a linear calculation? (which would then apply for all intercell numbers).

Thanks for any feedback!