Hello and advice needed for Catasetum

[Vermonter]

Hello all. I am very happy to have found what looks to be a great resource. May I dive right in with a question?

It is time for me to repot my Catasetum (Ctsm. atratum ‘Polar Cap’ x Ctsm. tenebrasum ‘St. Frances’). I am considering a mix of medium size fir bark mix with sphagnum and a bit of potting soil. Does this sound reasonable?

Also, I have the newly started bulb and 5 backbulbs. I would like to try starting some of these backbulbs. What is recommended for best results in starting Ctsm. backbulbs?

Many thanks.