The continuum receiver at the JCMT is SCUBA-2. POL-2 is an ancillary instrument to SCUBA-2.
The current status of SCUBA-2.
Future receivers
The specifications of a proposed 850 micron MKID continuum imager were provided at the EAO Submillimetre Futures meeting in Nanjing, China in May, 2019. The document is available here:
Guide to the new 850um MKID camera performance
Members of the JCMT community have written a series of white papers discussing the impact of this new instrument on a variety of fields including: Transient Studies, High-z Submillimetre Galaxies, Polarisation Mapping, and Evolved Star studies. These documents, along with a summary of each paper, are available here:
EAO Submillimetre Futures White Paper Series (and summary)
Retired receivers
In the science archive one can find data obtained with a number of retired receivers.