Here's an 'easy' next step to try (if you have them): install a #115 mainjet. It sounds like it is just a little too rich below the cam's active RPM range, which will stop it from being able to ingest all the extra fuel that comes from being 'off-cam' until things come together.
I say 'easy' just because it is simpler to change the mainjets than to go back into the slides and drop the needles another notch. If a leaner jet size helps, it may take both steps (drop another needle notch and go to #110 mainjet) to get it to 'start' on the low end of the cam. When the higher-RPM cams "come on" the engine goes from being severely over-carb'd and 'wet' to blowing out that excess gas, then burning the mix well. The trick is to prevent the low-RPM ranges from overloading the mixture before you can get to the more-effective high RPM range. This often means making the low-end lean (even nasty lean) in order to prevent the engine from loading up when in the race and you are forced to drop RPM too low for the gear you're in, then you must act fast on the shifter to get back 'on cam' and burn off that excess fuel before the other guys pulls out in front of you.
Don't overlook this: in the K0 carbs the float-height reference ledge is NOT the flat spot on the gasket surface of the carb. There is a tiny sliver of a ledge just inside the float gasket where those notches are, and THAT is the zero reference point for the float gage. And, the K0 carbs used brass floats with one side set at 25mm (the kickstand side) and the other at 26mm. In my roadracers we used 24mm and 25mm, respectively. I still use that in my K2 today. While it doesn't have a high-RPM cam, it also has no flat spots in throttle response.
This was a common tuning issue with roadrace 750s (fixed typo here) in the early 1970s, we dealt with it a lot. It was always easier to tune up to a hotter engine by doing one thing at a time, like install new, hotter pistons of some sort and tune to those, then install the carbs or cam and tune to that, etc. We were dealing then with lots of unknowns for sure, as Yoshimura was REAL tight-lipped about tuning to the parts they sold. You might remember seeing the famous Cycle Magazine issue with the CR "kit" for a 750 on the cover: I knew of 2 guys who borrowed $$$ to get those "kits" and we never saw them on the racetracks again. They never could get them tuned right.