What is the feature you want to see?
The experience bar should show how full the elemental meter is (440 being full, 0 being empty).

Why would you like this feature?
It gives a better visual indication of the element left, and how quickly it is emptied, rather than just being a number of game ticks at the top of the bar. (The number should be saved in a score instead and not be visible.)

Any alternatives you've considered?
Boss bar: Sadly that is global and not per-player.

Additional context

The level should be level 63, where 399 xp point is are available in the bar; to make it 10 steps, 40 points are subtracted for every 44 element used. This also means that until value 1, the bar will show 1/10th filled. To remove the level indicator, simply subtract 63 levels at the end, xp bar progress will remain in place.

For the Poltergust 500 (beta mansion) it should go the other way. With max value being 300, which shouldn't be displayed, this is a 40:15 mapping.