Looks like LG recently released a new full-sized stand-alone heat pump dryer, model DLHC5502 that takes the championship for efficiency in that size.
Per Energy Star Metrics:
Drum Capacity (cu-ft): 7.8
Ventless
Combined Energy Factor (CEF): 9.0
Estimated Annual Energy Use (kWh/yr): 266
Refrigerant with GWP: R-134a (GWP:1430)
Date Available on Market: 2023-10-02 (but still mostly a ghost model on web searches)
https://www.energystar.gov/productfinder/product/certified-clothes-dryers/details/2669197/export/pdf