I don't think Hubble or the JWST have much to do with the question of whether we should have built another LHC to collect data twice as fast, except as an imper

I don't think Hubble or the JWST have much to do with the question of whether we should have built another LHC to collect data twice as fast, except as an imperfect analogy to help frame the question in casual consideration—i.e. the reverse of the analogy I made in my comment. In fact, answering that question should come down to whether we expect the LHC to realize the majority of important observations "in range" of its instruments within its projected lifetime, and also in time to make useful contributions to the selection and design of future experiments. To answer your question directly: yes, AFAIK the LHC is fully utilized; when it's not running, it's down for maintenance or upgrades, and its observations are (or have been, in its active periods) in high demand. But it's far from clear that building another one would yield a good return on investment, especially given the opportunity cost of diverting funding from future experiments.