ya I know you can't advance it but moving the sensor isn't going to advance it.
you can change spark timing by moving the crank sensor - why are you saying that it won't, that's what gives the timing reference to the PCM, the crank sensor, the cam sensor in the distributor is the cyl1 reference for injector opening order.
that's about the same as buying them resistors of ebay for large power increases lol
not the same, it actually works same as FTC1 - what FTC does is to insert a delay on the crank signal wire so it sends it later to the PCM based on when the signal was received and the rpm (the delay amount i mean not the tuning table, the delay will be shorter for the same amount of degrees as the rpm increases), it is the same as moving the crank sensor the same direction as the engine rotates. What FTC1 cannot do is to advance timing since it doesn't know when the signal will come on the wire, it needs that reference to insert the delay - moving the crank sensor the opposite way of which the crankshaft rotates will give the signal sooner by that amount in degrees. there is a limit on how much the crank and cam sensor can be off, i don't know what that is but i doubt would be less than what room you have in the bellhousing opening to move the sensor.
unless you use a turbo i don't see the benefit to retard timing on the 4banger unless you have some knocking issues, if you want to tune it with the FTC1 timing retard feature you need to have more advance to be able to retard it (and obtain more spark advance compared to stock but less than when you start experiencing knocking) - i might misunderstand what you mean so maybe explain in more detail your plan.
EDIT: i just read my post (this one) and i might have not explained my point well enough so i'll use an example
let's say you want to have +1deg more spark timing at 4000rpm but you want to keep the rest across the board just as stock - you move the crank sensor 1deg against the crank rotation, that will change the timing across the board, you retard the timing for all cells in your FTC1 timing table by 1 degree and leave the 4000rpm unchanged - of course it is a hypothetical scenario, just to explain what i meant by moving the crank sensor.