Should we add more test cases: menu responsiveness, latex and moving tabs around

[krassowski]

Problem

jupyterlab/jupyterlab#9757 highlights some scenario where the entire UI becomes slow to respond due to a high number of DOM nodes.

Proposed Solution

Should we add test case for this scenario, or is it already somewhat covered by any of the existing benchmarks? Should we add a case for each non-covered manifestation of the problem (menu responsiveness, latex rendering, moving tabs around)?

Additional context

Tab switching is already covered (but it seems it has a different cause).