Sorry but this is legitimately a terrible way to encode this data. The number 0.8 is encoded as base64 encoded ascii decimals. The bits 1 and 0 similarly. URLs should not be long for many reasons, like sharing and preventing them from being cut off.
Links with lots of data in them are really annoying to share. I see the value in storing some state there, but I don’t think there is room for much of it.
What makes them annoying to share? I bet it's more an issue with the UX of whatever app or website you're sharing the link in. Take that stackoverflow link in the comment you're replying to, for example: you can see the domain and most of the path, but HN elides link text after a certain length because it's superfluous.
