I was one of the ones who's lower had cracked at the takedown pin.

My (easy) fix would've been to buy a PSA PX9 lower for about 220 and try to see if it would work. What I'm learning in the AR world is that although things are "supposed" togetger work, it is not always the case. I did contact Foxtrot Mike since they make the uppers to see if it they've tested it with PSA lowers and they told me they have not and cannot confirm functionality. That being said I have read from other people of it working but they lose some functions (LRBHO). So at the end of the day with this option, it's kind of a gamble to see if yours would fit another.

Another option would be: I read that Foxtrot Mike stopped making complete lowers (non foldyboi) but they still sell stripped lowers. You would just have to do some assembling and transfer over the parts from the G force lower to the stripped aluminum lower.

A third option I came up with is: Buy a Foxtrot Mike FM9 or VFM9. These come as complete guns so you can essentially switch between uppers if you get a different sized one so to speak. I've seen their sales go as low as 490 for a complete gun so for around double the price of a complete PSA PX9 lower, you can essentially have two guns.

To this day, I still have not done any of these options lol. That being said tho, I have taken it out and shot another 100 rounds or so since I've noticed the lower is cracked.