Stephen White has recently produced Temperature and Emission Measure responses for GOES 18 and GOES 19. These have been made available in SSW as of 17th October 2024. The file: https://sohoftp.nascom.nasa.gov/solarsoft/gen/idl/synoptic/goes/goes_chianti_response_latest.fits should reflect this. It would be good to update the GOES software (not sure what is needed) in sunkit-instruments to also be able to use GOES 18 and GOES 19.