I would definitely support this proposal. It seems that with FormBuilder you have made a great product in terms of its validation functionality and 'wizardry', which is devalued (I believe) to a large extent by the mark-up it produces to accommodate design. I can't bring my self to use it for this reason. It takes a couple of minutes in DreamWeaver to apply my own preferred styles anyway.
This is a shame, because it has a great walk-through wizard for applying server-side validation, - a facility that you can't access without having it apply exaggerated design features and mark-up.
If there were a similar wizard for just validation, or even a checkbox to tick at step 1 of the wizard to select 'Validation Only', it would help a lot.
I don't have a problem with using the alternative method of applying validation via the toolkit, but the walk-through wizard would be a useful bonus.