It will work, but it wil not give you extra speed. Also, the T5 operating system does not support the TRIM command, so deleted files on the SSD will not release their used space and eventually the SSD will have no free space left.
Styles are normally quite small, so why not use a USB flash drive? For loading of small files, a flash drive will be faster than a HDD. I've got thousands of styles (.sty) on my 32 GB USB drive and still just a few 100 MB's in use.