Not sure why we would ever want demurrage - which is basically a tax on liquid monetary assets - unless we want even further expansion of the state?  All that does, anyway, is make the keeping of cash a money losing proposition.  One could still invest the money in savings instruments.  What's the point of it all besides expanding government power, anyway?

I'd urge against it and would never avoid a currency which participated in such a tax system if I had a choice.

Having Gold or BTC's and not spending them is one way to "save" ... it means consumables that you could have consumed are either consumed by others or don't need to be created, freeing other resources up for capital investments.  That's what your "savings" is in reality if you are talking strictly speaking about hoarding money itself.  A [usually] more profitable mechanism for savings would be to loan your money to someone else who will build a lasting asset with it, that creates future consumables (capital investment).  This can happen 1:1 or via a banking system.  Either way you look at it (cash hoarding or investing) it is not a bad thing to save instead of spend. The best is if people are 100% free to spend and save their own monetary instruments as they see fit, thereby deciding what gets consumed now or later.  I am 100% sure this is morally better as well as produces better outcomes than where some central planners try to favour spending over savings artificially.