Time to build another frame :-)
There’s nothing wrong with the kit bike, but I’ve now put enough miles onto it so that I’m moderately confident that my brazing skills are actually up to building trusses that can carry significant weight & there’s nothing like practice to make my skills better. (Also a local bike shop wants to display one of my frames, so I should probably glue one together where the TT doesn'’t slide sideways while I’m brazing the front triangle together)