I've cloned multiple tanks starting with a 10 gallon with a cycled sponge filter. The original sponge filter cycled in a 29 with a pair of angels. I pulled a spawn, and added the cycled sponge filter to the 10 gallon they hatched in once the fry were swimmers.
After a few weeks, the fry went into a 20 with the sponge filter, a second new sponge filter, and a small ac mini hob. After 3 more weeks half the fry, one sponge filter and half the hob media went into a second 20 with a second ac mini. We now have 2 20's with an ac mini & a sponge filter on each. Add a second sponge filter to each tank.
A few weeks later, half the growing fry from each 20 go into another 20, with one of the sponge filters & half the media from the hob. 4 20 gallon tanks, each with an ac mini, and a sponge filter, around 75 small but growing angels in each. 80 gallons isn't enough for growing angels to sellable size, so more sponge filters get added to tanks.
A few weeks later, 2 sponge filters go into a 55, along with some of the media from the hob filters going into a couple of homemade powerhead filters. The faster growing angels go into here, as they are sold, some of the larger ones growing in the 20's replace them. The best looking ones go into a second 55 that has been running for years, future breeders, or adult fish to be sold.
At this point there are enough cycled filters with mature media that if I run into a great deal I can fill a spare tank, drop in a heater & filter with cycled media, and put the fish in for quar. Never had a problem doing this, at this point I don't even bother with water tests unless the behavior of the fish tells me something isn't right.
I did check some fish losses in your poll. In any breeding situation, you are going to have some losses, as long as it is 10% or less, you are doing fine with angels. Any other situation, I have had no losses. This is usually setting up a tank for a pair or pairing situation. Fill a tank, set up the appropriate filter & heater, and add fish.
I recently upgraded 3 of the 20's to 29's. Drain some water, catch the fish, and put them in a bucket with a heater & airstone. Drain the tank, disassemble related equipment, pull the 20. Put the 29 in it's place, fill, add filter, heater, & fish. No losses.