I have decided to add a timer to the level stats display after all - but it remains optional. Stats can now be toggled between "Off", "Percentages", "Percentages + Time", "Countdowns" and "Countdowns + Time" in the menu.
Besides that, it's now possible to switch between level stats modes without having to restart the level - finally it's the way I wanted it to work! The rest is rather cosmetic, just see the changelog below.
I think it is rather unlikely I will add any additional features to this mod by now. It's pretty complete considering what it's supposed to do, and adding even more would make it bloated. Unless there are any bugs I have missed, this should be the final release.
CHANGELOG v4.3 (OCT 12, 2018)[ALL] Level stats: Time display added (optional, select it via menu)
[ALL] Level stats: Switching between modes now works without level restart
[ALL] Level stats: "Countdowns" numbers placed before "Kills/Items/Scrts Left" text
[ALL] Level stats: STATS1/STATS2 graphics slightly resized
[HERETIC/HEXEN] Level stats: Aligned to top right corner (again)
New level stats with optional time display:

DOWNLOAD DEPRECATED, SEE NEW VERSION BELOW