Black Rubber Belts has been retired and is no longer being maintained. It will not be updated for Factorio 1.2 or Space Age.
Compatibility
This mod updates the belt_animation_set for the three vanilla belt tiers. This change should be automatically reflected in vanilla undergrounds and loaders, and it should also work correctly with other mods for loaders and other TransportBeltConnectable-derived prototypes associated with the vanilla belt tiers, unless they are directly referencing the vanilla belt sprite sheets.
Low resolution sprites are not provided and the optional hr_version property of the belt animations is not used. That is a completely legitimate animation format. For cross-mod compatibility it's best to always check whether optional prototype properties exist before trying to index them.
Non-vanilla belt tiers (e.g. purple uber-belts, grey tortoise belts) are never going to be directly supported by this mod. However, if you want to DIY your own skin for third party mod belts, a simple function is available for getting a belt animation set for any given tint - see data.lua.