Moving from bark to traditional mount?

[Reeses]

Hello lovely orchid people,

I just bought a new Neo (tag simply says Neo. falcata x Neo falcata) at the Indianapolis orchid show. It already has a spike full of flowers, and three more spikes!
However, it is potted in bark, unlike other Neos I've had in the past. I am a fan of the traditional Japanese sphagnum mounds, and would like to eventually move this one to that style. Are there any potential risks in doing that? Is there a certain time of year it is better to repot than others?

Also, the last time I tried to repot my neos into fresh moss, two of them died Still not sure what happened--all of a sudden all the leaves turned yellow and fell off, within days of repotting. I would certainly like to avoid that in the future! Any ideas as to what the causes could be or what I can do to avoid that?