The hard technology in JWST had to do with the cryocooler, which was needed to cool the infrared detectors to just a few degrees Kelvin. (Of course IR is the w

The hard technology in JWST had to do with the cryocooler, which was needed to cool the infrared detectors to just a few degrees Kelvin. (Of course IR is the whole point of the mission.). The cryocooler was unique in several ways, including sheer size and a complex routing throughout the spacecraft bus. There is no basis to compare the hard technology in JWST to the hard technology in a space interferometer. They are two very different beasts.