You have another option and an alternative to using either Topaz Denoise AI or DXO Deep Prime, which can work with or without a tripod. M43 and the G9 in particular make it relatively simple to take multiple images in a burst, and subsequently stack & average in Photoshop to dramatically reduce noise.
Of course you do need to use Photoshop for this. There may be other software that can do the same, but I haven't heard of it.
If tripod and no movement in the scene, you can choose to shoot at lower ISOs, but of course you can do this anyway with low noise at ISO 100 or 200.
For hand holding, select an ISO that will allow an adequate shutter speed, and fire off a burst in multishot mode. I tend to mostly use silent shutter for this, but would switch the shutter mode if there are lighting sources present that may cause flickering artifacts or banding.
In PS, bring the frames in as stacked layers, select all and auto align. Then convert all to Smart Objects (this process will take a bit of time, how much will depend on your computer resources and how many frames). I would recommend between 8 and 16 frames.
The final step is to go back to Layers / Smart Objects / Stack Mode and select Median. Because noise in the original frames is random while the subject matter is constant, the algorithm will remove almost all the noise, and in a very clean, non-destructive manner.
I have also had very good results with Denoise AI, but I've never tried DXO.
The link below is for an example I've posted on Flickr of a G9 ISO 2500 shot in very low light, pre-sunrise, hand held on a moving ship. No noise reduction was used, except for the process outlined above. In this example the process was also used to double the file size and image resolution, and that is an option by adding an additional step or two into the process, but not the main point here. This image was uploaded at it's full file size of 10322x7742, so you can click on it a couple of times to really see lots of detail.
https://flic.kr/p/2jkGniR
Brian