I wonder if with bitpacking you can achieve even higher ratio, considering each temp has 3 digit and temp range 51.2 to -51.2 if reasonable range 1 for signature 9 temp bit could store 3 temp in an integer. Deltas might consume less range maybe but might need extra bit tweak, afaik fastpfor also does similar run with simd , but what i understand time is not your main concern.

Edit: just read the 0.04-0.02 range , if I understand right only putting 1 real temp and then deltas could fit 12 first int and 16 temp following ints? Quick napkin math , could be wrong:)