The problem with that is then you are on your own for updates. So none of the updated threat data will be available.
Like any software you aren’t hostage to it, if you have the time, technical expertise, and money to invest in a replacement.
The Israelis have effectively done that, but in a cooperative environment with the USG and LocMart, so there is two way sharing, but not 100%, and no ‘forced’ updates for the IAF jets.
The cost and technology required aren’t a small thing and most nations (okay any nation that doesn’t have its own nuclear weapons) probably doesn’t need to bother.