just thought i would put this out there:
I've been seeing a similar product used in videos for dangerous9 straps and ciprys morpho leather goods. It goes on liquid and is then melted and moved around with a wood burner or heated nail. This filled cracks and is very durable.
In my search for this, I ran into the inks used for textile printing: specifically the heat fixed inks such as plastisol. This is a gelled vinyl resin that cures fabric soft, it just doesn't ever 'dry' without heat application) with the application of heat, 350F from one video I viewed. I will give it a try on a watch strap project I will be working on later this month.