Specially for the cpu module that tends to be below 10% and even with :2:3 looks inconsistent side-to-side other modules:

Here, the spacing between the icon and the percentage appears a bit like the margin between modules so it's not only unaesthetic but also confusing. The alternative of not reserving space for a second digit is distracting when the glyphs are frequently moving back and forth.

The real solution is to zero pad that percentage.

Then the real solution is to support printf-style format strings but zero-padding is the most important use case AFAICS.