Halation and chromatic aberration in XR headsets spread the light in all directions causing the boundaries of the letters to disappear giving an impression of rounded edges. In some cases, the size of the letters is also affected, rounded edges reduce the size perceived by the user.
The rounding effect significantly impacts legibility, readability and aesthetic issues at a typographic level.
Sans Serif typefaces are affected the most by rounding at the stroke endings due to the absence of serif that reinforces the stroke endings.
Letters like l appear to fly above the baseline affecting the rhythm especially next to curved letters (like c,s,o) which have overshoots.
This happens because of the combined effect of overshoot plus the glow which optically pushes the baseline lower.
The shape of terminals also gets distorted and appears to be smaller than the actual design because of rounding. For letters such as f-t, i-j rounding of distinguishing features creates confusion and hampers the reading experience.
A counter-measure can be using rounded typefaces. Since they give a good approximation of the final result and you get fewer surprises as a designer in the final outcome.