Attaching Leads to Wood Blocks (Trees)

Leads are awesome for moving mobs around and especially over long distances.  However, its very limiting that they can only be anchored to a fence post (or boat in bedrock).  It would be awesome to be able to attach the lead to more blocks, such as a wood block.  This would enable you to easily anchor your horse, donkey, cow, etc to nearby trees when traveling off the beaten path. 

The only alternative I've found is carrying a single piece of fence post around with me while exploring with the sole purpose of being able to anchor the mob while caving, sleeping, mining, etc.  Its frustrating, which often leads to my immersion being broken.  Both aesthetically and functionally, it would be nice to be able to simply anchor to a tree trunk.