You can consider V1 feature-complete and if you don’t really update dependency packages, you may have a long way until you experience any breaking changes.
You can consider this as a good thing; great stability.
I need to be careful not to overstate this one potential (unconfirmed) drawback: performance. I reported my quick benchmarks long ago on V1 on Windows.
My observation is that performance degradation is linear — that is, when you have 10k notes, it’s roughly x10 slower than 1k notes.
I don’t have data for V2, but I take Jethro’s word for it when he says its DB performance is better — I believe this is because the way he constructed SQL queries for both saving to and reading from DB.
If you are on Linux, I believe Linux would scale better. And you may not experience bad performance even when you have 5K notes. This might also depend on how many links you will have — my benchmark really could not test many links.
For ongoing maintenance of V2, you may benefit from (potential) further tuning. This is only speculation and might well be an empty comparison with V1. That is, you may not experience much performance difference on V1 or V2 anyway (depending also on your hardware, etc.)