If you have the time, you can replace the seat with a fiberglass hump type. You then move all electrics and the battery (Shoeri Lithium / Iron phosphate). This will open up the triangle. If you go whole hog, use a die grinder to remove the brackets left behind, smooth the welds with a Dremel and Bondo and repaint the affected areas.
I just completed the task with a 78' Kawi KZ 650 B and it turned out very nicely. Good luck !