I’ve become aware that the 3rd century anti-Christian writer Porphyry of Tyre wrote at least some work on astrology. This seems to be very obscure, tho, and I’m not quite sure what exists. Nothing seems to exist in translation. I did come across a reference to Porphyry, Introduction to Ptolemy’s Tetrabiblos (CCAG vol. 5 part 4, 212); but there may be others. The CCAG is the Catalogus codicum astrologorum graecorum — a catalogue of astrological manuscripts, in which the editors have helpfully printed excerpts.
Vol. 5 part 4 is online, and the index at the back reveals what looks like a full text — pages 185-229, no less, 44 pages in 55 chapters. It’s been edited from half a dozen manuscripts, and had been published before back in the renaissance. 5 lines is 43 words = 8.6 words/line, 31 lines a page = 267 words/page, 44 pages = 11,748 words, which at 10c a word comes out at $1,175 to translate … if I knew anyone who was interested and capable in what must require a serious understanding of Greek astrological terminology.