I've been searching for a decent and financially viable solution to the floating pinky issue when I came across the GABALE QR L Bracket on eBay, its essentially a Chinese clone of the RRS L Bracket for the A7RM3 & A9 available in Black, Red or Silver.
It works a treat and solves the issue for me at least of what to do with that floating pinky and as the portrait section of the bracket is removable without taking the base plate off, makes it all so easy to use.
Not only that but its also under 1/4 the price of the RRS Bracket, mine cost me £42 inc shipping.
Well worth a look if your having problems too.
Also my lil Brother dropped round his Nikon 500mm F4 for me to play with, talk about weight a ton!! I could barely lift it, got it on the bed mount and then the whole lot started to look like it was going to come down! so moved it onto the TMA48CL Benro tripod & B4 head, that held it no problem the only trouble was I couldn't move it and the tripod at all.
It might be manual focus but its still as sharp as a razor wide open, just a shame there wasn't more to shoot than the arse end of a sparrow in the tree at the end of the front garden!.
I had a lot of trouble with my Nikon adapters with the A7RM3, my 300mm F4.5 just would not focus correctly for some reason, so I bit the bullet and grabbed a s/h Metabones for Nikon F and its a world of difference, there's just no comparison with the cheap ones which for me dont seem to work on this body but the metabones works a treat.
Finally when my brother popped up last week he brought his new D850 & 200-500mm, found out I really do need at least 400mm in the back garden for covering the wildlife (lovely rig, body was surprisingly small) so theres now a Sony A mount 70-400mm heading my way as we speak to go on my LA EA3. That will round me off for lenses, time to do more shooting and less hunting for hidden gems on eBay etc.