Just curious, as there doesn't seem to be a channel for it, but did anyone have success bringing up their MPW4 chips? Or experiences to share of trying to do so?

Unfortunately I did not receive anything from MPW4.

I've received our MPW4 chips (F1) and successfully brought up Caravel on several of them. Some chips even managed to configure all IOs. Unfortunately our user design is essentially a brick because WB registers critical for design bringup are out of user WB address region. During design development 2.5 years ago I've tested it with Caravel picorv32 management core which had larger user WB address region and completely missed the fact that it was replaced by litex management core with only 0x100000 user address range 😞 .