Finaly! All Aerangis buds opened! Almost six months after the first sign of spike! It is a world record!! (of slowness). It lost two buds, but for me its OK, this is its first blooming!
You could try vitamin B complex (or pure B1 vitamin - tiamine). Besides its root growing properties, B1 vitamin is useful to 'waking up' some orchids (personal experience). 'Superthrive' has B1 plus hormones, it will work too!