What controller does your USB-C enclosure have?
I've tested a WD SN570 in a RTL9210 based Orico 10GB/s enclosure and a TekQ thunderbolt 3 enclosure. Here are the results:
| Orico 10GB/s | TekQ 40GB/s |
Idle | ~3W | ~8W |
Sleep | 0W | ~3W |
The ~3W power draw in sleep with the thunderbolt enclosure causes almost 6-7% battery drain per hour on my MBA M1.