Thank you all for all of your wonderful feedback!
I think I'm going to try the fender steps - my only concern would be if they're slippery when wet? To those that suggested/have used them - are they? If so, did you just apply some anti-skid tape?
The other option is this ladder: 5-Step Rail Mounted Boat Ladder - Norestar -
which 1) is not a swinging ladder 2) braces up against the side of the boat 3) is nearly 5 feet tall and so should meet at the side of the dinghy when pulled up to the boat and 4) keeps me away from that short, swinging, transom ladder (which puts me on my knees on the back platform = NOT a good thing with a crushed kneecap!!).
And the best part is both options are under $100! Woohoo!
Thanks again - you guys/gals are wonderful and have such great advice!