Why are you working in support without providing any support!? If I wanted a funny answer I would post this question on 9gag.
So, if anyone needs this here is the (temporarily) solution :
CONS: It requires changing SP Page Bulder core file (I'm strongly against changing any core files) that will be replaced with every update (until someone in JoomShaper make this little change in code).
PROS: It allows playing background video from Slideshow addon on Safari browsers for IOS and MAC devices.
All you have to do is add 'playsinline' (and if wanted muted, autoplay and controls) attribute the correct way in components/com_sppagebuilder/assets/js/js_slider.js file.
Because the file is minified fastest way is to find and replace:
h.playsinline="playsinline";
with
h.setAttribute("playsinline","true");h.setAttribute("autoplay","true");
*and if needed add:
h.setAttribute("controls","true");
and
h.setAttribute("defaultMuted","true");
Empty cache and that's it.
I'm not a java programmer, so if anyone knows a better way please write here.
Note for JoomShaper support: This is not "non-standard js tricks" so please consider adding correct code in future updates.