FY22-Q2 (VP, Product) KR: Increase SaaS SUS score to 72.5 by improving MR experience => 84%

As a joint effort across Dev section, we will focus on increasing our SaaS SUS score to 72.5 by improving the rendering performance of Large MRs by 40%, reducing MR memory usage by 65%, and making user experience improvements.

This KR is made up of three components and success will be measured by their completion:

1. Improve rendering performance of Large MR: 40% faster, 65% less memory usage
2. Improve performance of discussions action (issue 1 | issue 2) => 2021-05-17 Update: 5% #2445 (comment 577352527)
3. Burn down issues from MRs async critique 13/25, 52%