The best idea was alternating every exposure between preflash & mane flash with an indicator on the LCD showing what stage it was on.  The user would delete every other exposure.  The user could manually take 2 shots in rapid succession to get the same effect as TTL.  Power cycling it or changing mode would reset it to preflash.  It would work on AA's.  It wouldn't have been practical in the film era but it is now.

It's the dumbest goal a lion ever had, but it's about getting some return on investment.

The preflash & mane flash states.  Concessions were made with the commodore font to fit enough characters in.  The original reverse characters for M & P weren't as legible.

To make it more bearable, it shows the power requested by the camera after the preflash.  Even $600 flashes can't do that.  The camera seems to lowball the requested power.  Past experiments showed the camera scale is 8 units per stop, but it seems to either require more stops per unit or rounding.  1 problem is knowing what power to use for the preflash so it has enough room on both sides & doesn't saturate the sensor.

Digging deeper into the power control issue, there's nothing online about power control in camera flashes.  There's just not a crossover of interest from electronics to photography like there is for oscilloscope teardowns.  

The power pin goes into pin 4 of an SA01 thyristor array, aux thyristor gate.  Aux thyristor anode goes to a cap connected to the flash tube.  The cap might drain the tube when it's grounded.  Disconnecting the power pin from the original brain didn't change anything.