I used to report my Phals as soon as I brought them home. I use leca mixed with very small seramis which are placed in a plastic pot with holes.
Some do well, but some lose lots of roots due to root rot and then start growing new roots that are adapted to new media. Because a new Phal has to adopt from being tightly packed with moss in a plastic pot without ventilation to airy cray pebbles, it takes forever for the orchid to recuperate from the repotting trauma.
Is it better to wait till the flowers are gone? Is there any less traumatize way to repot?