Need help choosing a power meter for new to me mtb

I recently took ownership of a practically brand new 2019 cannondale scalpel si hi-mod World Cup. It currently has a sram xx1 crankset (3-bolt). I run quarq on my road bike and called quarq today, only to find out there is no compatible quarq option due to the AI on the scalpel. But yet I see pictures of scalpels using quarq. Can anyone tell me how this is done?

I guess my second option is to just send the crankset out to 4iiii for a factory install of the dual podiiiium power meters (currently out of stock).

I’m just unsure of 4iiii accuracy, as I’ve never ran one. Can anyone comment of good or bad experiences you’ve had with 4iiii?