Are you saying it might have been able to cut square until the table bolts were retorqued?
If so, wouldn't that suggest your pivot is bored in fine and you have a table problem?? I'd think that would be much easier to address.
Or, going another direction...
Since it flexes so much, a red-neck idea comes to mind...? you could replace the stand? with something home made.? Have the top of the stand be a small slab of concrete maybe 4" thick.? Include mounting bolts when pouring it.? That concrete slab will not flex, so you can double nut the mounting bolts to flex the base of the saw however you need to.
