I managed to run the American/USA version of Sonic the Hedgehog Megamix, using the SegaCD Bios "us_scd1_9210.bin" which hopefully worked. I managed to improve my times in the 3 acts and as well as in the Special Stages of the same, using the ABC Button Spamming trick.
I took less time with this since I had the previous base as well as the Evil_3D TAS.
I say goodbye wishing you a nice day/night. Bye!
You can see the improvement here