If you’re looking to spend money on a machine to assist with BGA Rework on iPhones I would suggest taking a look at a CNC Mill as it will cut out the chip you need to replace along with any underfill that was present. Obviously, you lose the chip, but if it’s a situation where Touch IC or Audio IC need to be replaced then it can be more reliable than heat. Additionally, the more dense components before especially with the designs Apple has been using recently the more likely there are to be issues with overflow heating where while heating the board to resolve one specific issue you actually introduce a problem in a nearby component.
@jayeff I think that OP was referring to heating a bag of rice to use an an improvised iOpener. I know I'm necro-ing this question, but since I stumbled on it because iFixit SEO is so good I thought that a link to a disassembly might be helpful for anyone else that might run across it as well :: - https://www.fixez.com/guides/htc/htc-10-repair-guides/htc-10-screen-repair-teardown-and-reassemble