One balance issue is that auto-crafting is relatively easy and removes incentive to explore. By removing the crafting recipe and making the patterns only available via loot tables it would force exploration and make RS a better fit for exploration centered mod packs. Would obviously need to be done via config so it could be disabled on packs where exploration isn't the focus.

All of that can be done by a pack author, doesn't seem like something we should add imo.

Agreed.