@bakman2, @Askjerry,
Thanks, indeed local storage in the client would be a third option. But like @dceejay says then perhaps I remember too much on the client side. E.g. when something changes in my SVG node, I need to know that on the client side to refresh the local storage there.
And we had a couple of other feature requests to be able to get the current status of a specified SVG shape, e.g. from @d0d04m3. To solve that, the only solution would be server side DOM tree. So therefore I would prefer to keep the cache on the server, otherwise I need to implement both (client and server) cache.
So I "assume" @Steve-Mcl and myself should do something similar like @hotNipi has already done, by adding a data-storage option. Although I assume that even goes a step further by storing the data in the contextstore, so then I assume we should store the server-side DOM tree also (to be able to restore it after a restart)?
Please let the ideas coming!! Because I would like to implement this in the 2.0.0 release of the SVG node, and some folks are already waiting a long time for other stuff that I added into that release branch...