this is wrong because the BTN never has ATC when the SB has 1 chip.
the BTN already is limited to his open raising range.
your EV gained in the SB will not differ when raising to 5999 or 6000.
every scenario you have the same logical outcome.
1. BB folds BTN folds
2. BB folds BTN calls (BTN puts you AI on flop or AI pre-flop)
3. BB calls BTN folds
4. BB calls BTN calls (BTN puts you AI on flop or AI pre-flop)
these outcomes are exactly the same whether you raise to 5999 or 6000.
What you are doing by making that calculation is creating a completely different ICM situation (of course you will get different EVs).
your argument is this:
1. BTN raises , you estimate his raising range at 25%.
2. you decide to raise to 5999 rather than 6000.
3. the BTN magically now has 43o in his range and has to go all-in.
4. you have created more EV because now you are reshoving against a ATC range and not his 25% open.
you can see why this isnt correct yes?
It looks like you are trying to create an FGS situation which does not apply to your original problem. (you were trying to find out if raising to 5999 or 6000 changes the EV). I'm telling you it doesnt matter, and logically that makes sense. It making non-AI raises only changes the EV when you can manipulate your opponent's call/fold ranges, IE. being the short stack with a chance of folding if your direct opponent is AI before you.
sorry to burst your bubble, but the math you did isnt correct.
in fact, nash ranges calculate EV of going all-in or folding, and not of reshoving. so it looks like there are some more errors.
if you want to calculate the EV of reshoving you have to use SnG wizard or do the calculations manually using the BTN open raising range + BB overcall range + BTN over-overcall range + BTN raise/fold and raise/call ranges.
then you calculate the EV of raising to 5999 with tehse scenarios and you will find out there is no difference in this situation because all ranges I mentioned are exactly the same. The only way you can gain more EV out of raising to 5999 is if you think this will make the BTN or BB fold more hands than making it 6000. (logically this isnt the case)