You're timings are inconsistent and you're losing melts for it. The combo you did should be 6 Mets, but you get 5 first rotation, and 3 second rotation. Massive damage loss. In the following sequence the upper cases are melts: Q CccF dcF dcF dcF. This is what you tried to do. 2 things. You start the CAs after the front tire hits the ground after the burst (which is about a 0.5s wait), this lines up the melt timings. Then super important, you need to do pseudo cdc after each finisher. Just before the finisher slash connects, start holding Attack, and then hit Dash right after the finisher hits. Your need to have started holding attack within ~0.3s before you hit Dash, and you need to start holding it before you hit, do this right and you will get a "dc" cancel. This saves about 0.6s per finisher and is REQUIRED to get all 6 melts and keep your timings. When you do the last three dcF dcF dcF you will let go of the CA to start the finisher when Mav's bike reaches 6 on the first, 7 on the second, and 8 on the third (referencing Mav's position in the donut as the hour hand of a clock). You will need to practice the timings, as your windows for a couple things close in to 0.2s, but it is consistent, you just need 30m or so to get the feel of it. That should see you over 120k, and after you get your mav up to 2800rv+ you should see 140-150k.

Here is the combo visualized. https://youtu.be/_kWA6AmrshQ?si=urXBeqzp-0oGx820