We are talking about a stealth aircraft the US may face in the future which is as opposed to ballistic missiles that Saudi Arabia has intended for Israel and Iran. This is why I'd be more cautious about this. Saudis are also seeking interest in the F-35 after Israel acquires them the US will sell it to gulf customers.
As for Indonesia it was invited by South Korea along with Turkey to work on the KFX, I believe they signed an agreement if it fails or not 310 project would certainly be an alternative. I pointed out in my prior post it would be better for SAC to partner with Asian nations: Malaysia, Indonesia, and Thailand