It's a good idea for future satellites, but upgrading existing satellites is probably not feasible. And these polar orbit satellite typically live a lot longer

It's a good idea for future satellites, but upgrading existing satellites is probably not feasible. And these polar orbit satellite typically live a lot longer than the relatively short lived starlink satellites, potentially opening you to a (perhaps unlikely?) scenario where starlink moves to new and incompatible hardware for inter-satellite communications, and your satellite is then made obsolete. Vertical integration is not cheap, but it does have it's upsides.