With fox farm, only half of the time i add the perlite so u may be able to get away with skipping that when u transplant, i know i just switched to smart pots and thoes supposivly help get oxygen to the roots, i dont think u can really reverse any root damage but as i understand it, its like the top half, meaning the roots in other places will just grow more so i wouldnt worry
Adding some microbes will help out a ton something like voodoo juice or great white .. really helps the roots and will stop the lag time a little, so after u transplant give it some of that, i know after u transplant ur plant wont grow much because its mainly focusing on its roots at that point so giving it the microbes makes the roots blow up real quick and in return the plant can start growing its top half more
Topping does always set it back a little so thats normal to see slow growth after u top, also for the future i try not to top untill after they have been sexed, any stress will make them lean more twords being male but no worries.
I wouldnt put more holes in the cup, id just transplant em very soon give em some.microbes and they will be blowing up in about a week after all that, id def give them more time in flower i give eight week plants about 9 ....
Ithink ur date, april 25th is def do able, thad give u about three more weeks of veg, but the dry and cure takes about two weeks so keep that in mind