We never put our puppy on lead when meeting unknown dogs,it would have been impossible as where we walk is a high dog traffic area and would have been taking the lead off and on every few minutes.
We also didn't have the luxury of letting our pup socialise with only we dogs we knew,as we didn't know any and there were no puppy training classes close by.
We were lucky that Ruby never had a bad experience apart from being chased by bigger breeds a couple of times but i do feel pups need to be taught manners and handle situations themselves,not us deciding for them as after all,we don't speak dog,they do.
My OH made it a mission that she met everything from a yorkie to a rottie but would call out to the owner was it ok to come over.We always avoided a dog on lead out of respect but where i live there are MANY owners that do not know or care about doggie etiquette what so ever
and don't even know what recall is so keep up the good work you are doing with recalling your pup.