pilsburypie

I just got this gimbal too, it's fun!  Haven't had a chance to do any real shooting yet but tests at home seem great.
If you need it even further forward you can run the mounting plate the other way around (tilt motor on left side instead of right side).

I too was in this conundrum a couple of months ago A7sii vs A7rii. Went for the A7sii as I'm 80:20 video:stills. For me, there were 2 main points with going for the A7sii.
1. High iso ability. Not that I shoot in the dark, but to use a small aperture inside requires high iso.
2. The ability to use full frame in video with decent results - Similar to you I want a light setup. I don't want a bag of lenses to carry round. For me a 24-70 is a great focal range. If I got the rii, I'd be using the super 35 mode to avoid noise which then blows my wide angle. Sure I could use FF, but then the noise suffers. I would need a 15mm lens to keep the wide angle in addition to my more conventional zoom.
I currently only own the small Sony 2.8 35mm. I'm awaiting the new 24-70 to see how big it is and how much it costs. The current f4 24-70 receives mixed reviews. I'm sure the new one's announcement is imminent.
Both are amazing cameras. The A7rii wins hands down on stills, but the A7sii has that incredible low light ability and at FF.