My '31 Ford has a well set back engine that made filling the transmission a messy job. I wandered around Home Depot looking for "inspiration" (also had to fix some home plumbing). I ended up with a 20" flex SS toilet water supply hose, much like what is used with AN fittings. A half inch pipe nipple and a small funnel J-B Welded into it adds just enough extra length. The wall end (1/4 or 3/8 npt - forgot which) is the perfect size to just fit the transmission filler tube. While you still can't fill the transmission quickly, it is 99% drip free - for some reason, there is always that last drop that falls on those nice shiny valve covers. Total cost - less then $10 unless you have some odds and ends lying around, then cheaper still.
And that small end - you can add a short pipe nipple there and add more fill tube depth - I haven't as yet