Many times, but always one short of 'enough' it seems ;)
AIUI they did pressure the AVR manufacturers for control of that but were resisted. In the end a commercial decision has to be taken - accept the status quo being offered or simply not do business with the client. I have been in that situation many times and it is a hard choice. In the end, the company has a duty to its employees and shareholders as well as to its clients and turning away substantial lucrative business because the client won't play ball according to the rules you want can often lead to bankruptcy. IDK why the AVR manufacturers are so keen to retain control of XO setting - maybe it's part of a wider issue that we are not privy to.
Better idea, IMO, take the money and put it towards a nice external power amp and stop obsessing about it.
Edit: Oh, dear. If I start sounding like GaryJ, please let me know...
:) I've heard 9 before - but 6 made me laugh.... ;)