I found mine easier to grow after I stopped waiting for it to dry between watering... But then again mine is still a seedling so I have no idea about the flower buds!
Yours is magnificent! I really do love the red blotches!
The orchid is very well grown too!
Have a look at Bernard Lagrelle's note on Tetraspis: bernard.lagrelle.pagesperso-orange.fr/Tetraspis/Tetraspis.html:
relative humidity is higher than 75% all year round in situ !!