I think the hacktintosh folks have used the P41 for their on-board NVMe boot drive without needing to fix firmware or anything, so it is "compatible".
That said it is a rather uncommon choice for Mac use, since it is not sold everywhere in the US and not often having discounts, unlike Samsung and WD.
The Thunderbolt (3 or 4 is the same) specs limits the potential bandwidth for external enclosures with PCIe gen3 at x4 lanes, and further more with limited data lanes so in practice, you are only ever going to get ~22-28Gbps which is approx. 3000MB/s sequential read and write. So yes it is a limiting factor on the Mac itself, nothing is going to break through that, essentially you are only going to get pretty much less than half the potential performance out of a gen4 NVMe SSD.
That said, many including myself still would prefer to get a top tier gen 4 stick for this purpose because:
1) the gen3 sticks, even by notable brands like Samsung, have all been undergoing shady component changes which downgrades its performance, to the point the Thunderbolt is no longer the bottleneck;
2) the gen4 sticks have gotten incredibly affordable already
3) larger capacity are only available on gen4 choices
You may notice WD SN850X being mentioned more times than others in threads like this one, because it ticks all the boxes mentioned above. Currently this model has almost no manufacturing issues (unlike Samsung), no known component downgrade (Samsung and WD do this, but not on this model), no known firmware upgrade need (970 EVO plus namely), and runs at a so-so decent temp. Most importantly Amazon et al have been discounting the 1/2/4TB heavily in the last weeks. The SK Hynix P41 may be up there as well but there is not enough Mac user data confirming this.
Enclosure wise, you can see the Acasis TB4/USB4 combo series is quite popular here, I got both the TBU-405 and the TBU-405 Pro M1, both run reliably so far. But really anything TB3 enclosure can give you similar performance and temps, as long as they use JHL7440 Intel controller.
www.acasis.com
