Stupid Check - pattr

I think I know the answer to this really, but I just want to be super super sure.

I've got a really complicated patch that I'm using - it has 16 embedded instances of an embedded bpatcher which is basically a 64 step sequencer. All of this is stored using the pattr system (with every stored object meaningfully named), with autopattr objects in the embedded patch, a pattrstorage object in the top level patcher and a preset object to recall sets of the sequencers. It's a lot of data, which I save off as a .json file

I want to add one interface object to the embedded patch (the one that's embedded 16 times), and I want to be absolutely sure what this will do to the pattr data. I think it should be fine, but I guess I'm still paranoid from the old preset days when something like this could totally screw things up. What I think will happen here is that older presets (without the new object) will just noth have a value for the new object and won't affect it, and newer presets will store it as a new entry. Can someone confirm this for me, just before I take a deep breath and actually do the thing?