Bitcoin-friendly PoX burning

Recently I was reading some more about the PoX implementation and found this:

After this point, PoX is no longer active, and miners must burn all of their leader block commits. They do so by sending Bitcoin to the canonical burn address 1111111111111111111114oLvT2.


I am wondering, would it be possible to change the PoB mechanism used from one that sends bitcoin to a burn address to one that uses OP_RETURN outputs instead? My understanding is that bitcoin sent to a burn address must be forever stored in the UTXO set, thus contributing to permanent UTXO set bloat, whereas OP_RETURN outputs can be safely pruned by nodes since they are provably unspendable. For this reason, burning via OP_RETURN is generally considered the “bitcoin-friendly” way of burning BTC. I would like it if Stacks could be good bitcoin citizens and avoid bloating the UTXO set if possible. Thoughts?

More info:

In 2013, an easy way to add data to any Bitcoin transaction was introduced. By making standard a previously invalid script instruction, OP_RETURN, a Bitcoin user could add up to 40 bytes of data to his transactions.

Before the standardization this new output type, including data in the blockchain was not a straightforward task and involved using numerous bogus addresses to encode arbitrary data. The introduction this new output type made it easier and allowed Bitcoin nodes to prune this kind of outputs from their memory as they cannot be spent thereby limiting what developers called blockchain bloat.

cc and thanks to @jude who brought Stacks’ use of a burn address to my attention :slight_smile: