Daniel Ockeloen is developing a grip extender for the new Sony A1II and Sony A9III. He writes:
As promised, an update on the design of the extender for the A1ii (and a9iii and probably a7V) I really want Sony or someone to make. This is now a fully working prototype: 17mm height, Airtag inside, Arca plate, Peak Design plug space, and easy battery swap. The Baby Extender Grip (BEG) is my way of begging some brand to make this. I am open to some people with 3D printers to share the files so you can test them. The core is now designed around an Airtag alu part from JJC.
The extender is compatible with popular Sony models such as the Sony A1 II, Sony A9 III, and Sony A7V.
He also made a special cooling grip:
Made a 2h22m 8k 25p 50hz, 520M 10bit 4:2:2 recording with my first test a1ii cooling grip. I just wanted to see if cooling in between the lcd and body would work. I think it can go unlimited in my test case at 20c room and no direct sunlight. I stopped it at that point. I also had to attach a usb bank to the a1ii because at 1h10m internal battery was at 10%. Did this because i was bored and well engineers that are bored start to fiddle and to provide feedback to Denz Ahmet. Ill report this back to smallrig sony design manager and maybe sony or smallrig or… will add something like this to their new cases as a option or build in. Canon made a 570 euro cooling grip for the R5ii that kind of does something like this and even this small test shows it could be done for the a1ii. I have no deep feelings if a a1ii should be used for 2hour 8k video thats up to people themselves and their usecases.
Cool project!