I don't believe there is anything special I do with the phals in S/H.
I have rescued several phals that I transfered from crap bark/moss to S/H without having new root growth but have always cut the flower spike first to conserve energy. Going from moss to S/H is usually easier on the plant as the roots are somewhat aclimated to a moist environment but it is still stressful. You will usually lose roots in this process, thus the reason for waiting until new root growth starts to emerge.
I have never really understood the reasoning for transplanting to leca then to S/H. There are a few people on the board that do it and have had great success. It all depends on your individual growing techniques. Maybe I'm just to lazy to repot another time
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Joann