I know the Oly 14-42 isn't officially supported on the X5S, but I wasn't too pleased with some of the flare I had been getting in the Panasonic 14-42, so went and bought one to experiment with. There are enough people on the forum saying they have had success with the X5S, so thought I would give it a go.
Result: Fitted to the X5S, balanced perfectly with the lens extended (fitted/powered up/battery out once extended into work mode/balanced/then go) but I seemed to be getting a lot of gimbal buzz/noise when initially switched on and on the ground. It did settle to silence after 5-10 seconds or so, so I thought it could be OK. All zoom controls were working perfectly so the app and controller accepted it fine.
The only problem came when shooting video - every now and again there was a barely perceptible micro vibration that was just visible on the video, but bad enough to make it unusable. That was shooting wide - the zoom level that I balanced it at.

I was just about to return the lens when I thought I would ask here first.
I balanced it with one ring meant for the Panasonic 14-42 plus an ND filter, and it was just right.

Has anyone any suggestions before it goes back in the post? I can't figure out what the problem might be as it appears to be balanced perfectly!
I don't get any buzz/vibrations with the Panasonic and it works perfectly throughout the zoom range.
Many thanks
Andy

I am very interested in the answer to your question. I have the 14-42 Olympic too and I got the same little micro vibration you are talking about.

Did you really fix it using stuff ?

Do you recommend me to buy Panasonic instead of Olympus ?

That is sure I cannot fly for professional purpose if my shootings are so much unusable. Thanks for your reply

I'm afraid not - I had done all I could to balance it but kept getting those micro-vibrations, so I eventually just returned the Olympus and am back on the Panasonic which works fine.
So yes, if you need a zoom, the Panasonic works well.
I will get some prime lenses for occasions where the flare causes problems.
Sorry I couldn't be more help!

I use the Oly on the X5s with no issues. Communicates with the I2 & works well. No balance ring but I use a step up ring and a Firecrest  filter.

Do the zoom is smooth while recording and zooming at the same time ?
I have the handwheel so it might be useful to get a good vertigo effect (doing it with the zooming command of DJI GO 4 doesn't work because it is not smooth)

Can you share a link or a photo of your step up ring and the firecrest filter please ?

Thanks a lot