The Narrowband Channel | Olympus Cameras on the DJI RS3 Gimbal, Can you do Astrophotography with it? @TheNarrowbandChannel | Uploaded October 2022 | Updated October 2024, 1 minute ago.
There is only one camera listed as compatible with the RS3 and that is the EM1 Mk2. However you can actually use the Em1 Mk3 and with a optional cable the OM1 and Em1x will work. Yes even the big built in battery gripped EM1x will work and fit too. I did have to buy just one attachment. Really its a supplemental plate that eliminated the quick release.

Here is a link to it. I do not receive any kick backs for this.
smallrig.com/smallrig-manfrotto-quick-release-plate-for-dji-rs-2-rsc-2-ronin-s-gimbal-3158b.html

If you need any counterweights then I recommend these from Small Rig.
smallrig.com/smallrig-counterweight-kit-for-dji-rs-2-rsc-2-selected-zhiyun-gimbals-3125.html