I read somewhere that there is no risk of forks because ADA has a built in way of deciding who gets to propose the next block if multiple stakers get selected in 1 round:
The one who rolls the lowest number that satisfies the requirement gets to propose a block.
But if you control a lot of stake, couldn't it happen that you get selected twice? In that case you can first publish the first VRF, purchase a product in that block, then reveal your lower VRF and make a fork where you keep your funds (ie a double spend).
Anything that stops this?