Hello I'm new to the forum.
I have read many things about MXM cards on Alienware 18 R1 and M18X R2.
Many got the RTX 3000 and RTX 5000 MXM cards working. @therhor70 got the RTX 3060 MXM (GA106) from X-VSION to work on M18X R2 without any VBIOS mods.
Sadly, a member called @ssj92 tried to upgrade his AW18 R1 with a RTX A4500 MXM (GA104, unknown vendor) but it didn't install the drivers due to lack of power and lack of 4G encoding on the BIOS.
I'm going to buy an Alienware 18 R1 and a RTX A3000 12 MXM (GA104, 60-130W) from X-VSION and I will see if I'll have the same issues as SSJ92 or not at all.
PS: I also have a working HP RTX 3000 MXM
Link to the MXM GPU