Ven. Yuttadhammo has replied back, pointing out that there is a “Fuzzy” search, somewhat accomplishing what I want (which is sometimes usable, such as on the “Tools” tab, when searching the PED, DPPN, & CPED). This would help one figure out (in a rather convoluted manner) that what one is really looking for is “cāga”, and not “caga”, which I would then use over on the “Search” tab, when I want to go searching through the Suttas (without having to use an Rx).
Note: The Fuzzy search is also good for “checking for doubling and aspiration (and maybe voicing as well?) discrepancies”. Wow, that’s really useful, and I didn’t think of these.