UPDATE: I haven’t heard back from Chadd, so I tried (again) contacting SkyRC directly and this time, after some back and forth on their website chat, I got lucky and managed to get a PDF for their version 1.20 manual.
It was an image-only PDF, of the kind that not only is gigantic, but doesn’t allow searching nor copy/pasting, so I did some OCR work on it and generated what I hope is a better one, and placed both it and the original (above) on my website: Index of /manuals/SkyRC
I also compared it page-by-page (using the excellent diffpdf tool) and here’s the differences between it and the v.1.17 PDF available for download from the SkyRC website; there were only very minor changes, and only on the last 2 pages:
p.41:
info@skyrc.cn info@skyrc.com
p.42:
This content is subject to change. This content is subject to change without notice;
Please refer to our website for the latest version!
info@skyrc.cn info@skyrc.com
(C)2020 (C)2022
[Version 1.17] 7504-0680-08 [Version 1.20] 7504-0680-09
So nothing terribly important, but I thought interesting to make it available to all.