If anyone has other suggestions to mitigate this

Firefox has “permissions.default.image” (link) option that disables image loading, but this Wikipage is very old so I’m not sure whether it works properly in current FIrefox.

I’d write a bookmarklet for that case:

javascript:
{
const name = 'ABC';
const d = new Date();
const year = d.getFullYear();
const month = d.getMonth();
const date = d.getDate();
document.activeElement.value = `${year}/${month}/${date} ${name}`;
void 0;
}

This bookmarklet inserts the desired text into the currently focused text box. Tested on Lemmy Web UI.

What program are you using to write or edit the comments?