There has to be some kind of performance sacrifice to make the cable that flat as far as electrical considerations go.
Speaking as a first time home owner that was forced early to do a large amount of drywall patching, repair, and painting, just put do it the right way, a little bit of spackle, a little bit of paint and you'll never knew there was anything there afterwards.
Before I layed out a penny I would make sure that those cables were HDMI high speed certified or that there was a 100% money back guarantee or I wouldn't touch em with a 10 foot pole.
One other... BIG thing... You don't want to cut a hole to run the cable, but in order to get this to be non-visible you'd have to do at least 2-3 leveling coats with a 12 inch knife and spackle... The hole is actually easier.