True, but that only tells where the target should be. It will actually lock once it's own radar picks up the target, hence LOAL.
Miss or switch targets? If later, I believe it's due to already known problem with INS.
TBH, I like ED's approach of "era appropriate and as real as possible" modules. In that sense, GPS is out of line for all the modules you mentioned.
But seeing how ED turned this all around by working on F35, yeah, bring the NS 430 in!