This is a bit of a weird one.
When you open the debug pie (Shift+F3), it essentially lists a bunch of things that cause lag. You can see the sub-elements by selecting a number 1-9, and 0 lets you go back. However, there are 11 or 12 elements to start with, and no way to get to the last 3 unless it moves up in the chart to 1-9. If you select "gameRenderer", and "level", which is probably 1 for both in most cases, you get 22 options (23 in 1.16.5 and 21w05b). Now, there are up to 14 that cannot be accessed. This is a bit of an inconvenience.

A possible fix for this would be to be able to use the arrow keys to "hover" over one and then use enter to select it? (This will also solve the problem of having dual uses for the number row of hotkeys)

This issue is related to MC-217956.