Actually I had a better look, and it seems that it never worked better
than what we obtain now, after changing tex to etex. Actually the
output did not change at all... So there is no regression, the output
is not so good, but this has always been like that.
Do you still want an example in that case?
Ah, so it means that TeX4ht didn't actually insert any HTML for texinfo
even in the past. The good news is that we didn't break it recently.
You can send me an example even in this case, but I cannot promise
anything. It can be really complicated to fix this.
Best regards,
Michal