excellent 🤩
for mine a S.imberbis ( but also all my rubiaceae) I use now tree fern root in plate.
I put my plant on the plate which is horizontal, with a little living sphagnum moss around it, so that it takes root well, then I hang it on the edge of my terra.
when the plate is dry I saturate it with rainwater
for fertilizer I use NPK : 13-19-19 commonly and some times 25-5-5 (exceptionally)
FRANK how old is your plant ? you had it initially with flowers and drupe?