( It sure solves the lag problem by a ton~! )
Just disable all the Git related support ( Git / Mercurial / Subversion ), if you're NOT using any of them.
Step 1: Open "Add-In Manager"
Step 2: Look for and expand "Version Control"
Step 3: Select and Disable EVERYTHING~!!!
Btw, I'm still using MD 2.8.2 ( at this moment of writing ) because the latest MD just has to mess with me with its code folding bug. ( > _ < !!!)