Some lens musings after my short-but-fun 5-night camping trip to the Chilhowee Recreation Area near Benton, TN,:
1. I learned that I love the CV 65mm! It's a fantastic addition that is, for me, an optical replacement for my Otus 55mm. It's not better, though it has better sunstars, but it's really really good. The size/weight savings are tremendous. It's a fun lens to use and if Voigtlander had a (native) 21mm and 35mm of superior or even near-equal optical performance as Loxias, I'd switch in a heartbeat. Love the Voigtlander handling.
2. The FE 100-400mm GM was really great to have - I'm super glad I added that lens to my kit. Often 100mm is perfect for landscapes, and 300-400mm opens up unique composition possibilities; so the whole range is fantastic to have. Can't say enough good things about it. However, since I don't shoot birds, I had zero wishes for added reach (via a6500 or 1.4x/2x extenders).
3. My Batis 135mm got pulled out only once - just to force myself to use it - but I had no actual need for it on this particular outing. I keep wondering if the 100-400mm, which is so damn sharp, renders the lens needless for me.
4. There is only one lens I wished I had: the FE 35mm f/1.4 ZA I can't just go buy one, but I can sell something to pay for it. So, which would I enjoy owning more: the Batis 135mm or the FE 35mm 1.4 ZA? The Batis is optically superior and can create even more sense of depth as medium telephoto and it's just about the finest native lens available for a7/a9, so I love having it in my kit, but I love 35mm as my ideal general purpose walkaround lens - it's way more useful to me than 135mm is. I'm torn - right now I'm slightly leaning towards selling the Batis and buying the 35mm, but I need to push that to 75%+ before I'll act.
5. The new CV 40mm 1.2 looks enticing, with a lower price tag than the FE 35mm, but I think I prefer the overall bokeh rendering of the FE 35mm, and AF would be really nice on my main walk-around lens.
6. The new FE 24-105mm G is quite appealing, if I had the money for it, I'd buy one.
I think I'd swap the Batis 135 for the FE 35 f1.4 if I knew I would use that lens more often. You could always add the 135 back into your bag at some point in the future. Maybe you're still a bit gunshy with concern over decentering like your first FE 35? I would think any manufacturing issues would be ironed out by now.