[KevinH]

FWIW,

You can use css descendant combinator classes to actually style your example span:

p.P1 span {
}

or

p.P1 > span {
}

so you can safely only remove "empty spans" if there are no css combinator selectors involving spans.

This also holds true when javascript can be used to style as well.

So you might want to warn people to verify that they are not using "empty spans" in those ways first, to be safest.