From moss to LECA

[SoCalOrchidMan]

I have many Cattleya alliance plants in sphagnum in which I get excellent growth. Roots so thick they push the plant up and out of the pots.
However, I do not grow these plants in anything larger than 4 inch size. I would like to transfer to LECA or 3/4 inch rock to continue on to specimen size. Getting any or all of the moss off the roots would be nearly impossible without destroying the root system and thereby setting the plants back significantly.
The obvious method would also be the easiest: set the plant undisturbed in the LECA. Has anyone ever had to do this and have you had or would you forsee any problems with this? Any advice is appreciated.