That's an excellent book, and I do the same. I err on the side of just over for the 2% as iirc the safe limit isn't too much lower. Most things are totally fine at 2.5% too, particularly sauces (berries is probably where you may want to be on the lower side).

Vac bags for me have worked every time for me, I like to make these things with my kids, let them pick things to lacto ferment. Strawberries is the most recent that was excellent (and we'd picked several kilos), the liquid was fantastic for a dressing and the strawbs themselves worked great on meringues.