ps - nobody has answered my original question about whether or not you need to find undiscovered systems in order to enjoy them.
Since my early days exploring (2015), I have ignored previously discovered systems. This is purely for roleplay reasons, (it made no sense to me to 'explore' something that's already been 'explored'), although certainly while I was gaining exploration rank it made the process much faster as every system I scanned I got first discovered bonus for everything in it.
So it's not about enjoyment as such. It was simply one of a number of criteria that I considered when deciding whether to spend time in a system. I don't care particularly about tags, the chances of other players seeing my name (which would mean nothing to them anyway) are pretty remote, and at this stage of the game I need neither rank nor credits. The only reason I would bother to play is if I found the process fun.
I followed this same protocol once the FSS was introduced. I made three short trips to map notable bodies that I had previously discovered, exploring along the way. I was able to map all but two of my previously discovered ELW's (I guess they really were quite close to the bubble). Of course, even mapping those ELW's (and some AW's and WW's) ended up feeling pointless, after all, there's no way to interact with them...