Many times I'd like to be able to offer more than one form to display canned search results -- but NOT every web-enabled form in the database. The all-or-nothing approach is very limiting.

I think you can solve this by having a couple of forms specified in the "Form properties/Advanced HTML options".
Because I've tested a variety of forms and have to many available in the database I've in my case normally made 5 different available by adding the following under "Advanced HTML options":

<img src=images/storaensologo2.gif alt=Storaensologotype>
<table><td>
<FORM ID="dbtw_ID_Toolbar_Top">
<SELECT ID="dbtw_ID_Select_Form_Top" onChange="dbtw_form_change(this,'/dbtw-wpd/exec/dbtwpcgi.exe', dbtw_params)">
<OPTION>.Brief(w)
<OPTION>.Place(w)
<OPTION>.RelevanceRanking
<OPTION>.Summary(w)
<OPTION>.Table date (w)
<OPTION>zLink_to_file
</SELECT>
</td><td>
</td></table></FORM>

This means that I have the same written in all of these forms, but on different lines. In the query form I have put
<INPUT NAME="RL" TYPE="hidden" VALUE=0>
which means that these named forms are the only ones that are available for the user.
I think you in the same way in a canned search string can use tha same technology by having made the above in a couple of forms and then use one of them as starting form in the query.
Through this you can make various sets of forms available for different purposes, even if it takes a bit of work to do it and means that you will have fairly many forms available in the database itself.

This looks exactly like what I'm trying to accomplish, and definitely worth the effort involved. Thanks for posting.

Chris