Small sensor systems, like the micro-four-thirds OM-1, have their advantages and disadvantages. In my experience, the advantages are significant and justify supporting this system, whereas the disadvantages are limited to mostly two technical factors. I believe that these disadvantages can be made less important if we should see more progress in sensor design.
One of the two disadvantages is a relatively small number of pixels (20MP in OM-1). Not a big deal, for sure, but a future OM-1 should be more appealing to consumers if the number of pixels would increase to about 30MP.
The other disadvantage of OM-1 II is more significant to a non-wildlife photographer: the smaller sensor captures less light than the larger sensors. To be specific, at the base ISO 100, my Sony A1 can theoretically capture 8 times more light than my OM-1 II, whereas my GFX100S II can capture 16 times more light at this camera base ISO 80.
The cost of capturing less light is more visible shadow noise.
This second problem can be helped if OM could do what Panasonic did in their G9 II. First, change the base ISO from 200 to 100. This would mean a two-fold increase in the maximum amount of light the sensor would be able to capture. If at all possible, a further reduction in the base ISO would be welcome in future OM-1 bodies. Also if possible, implementing a dual-gain sensor design (as in practically every modern full-frame camera) might help to reduce the shadow noise at the higher ISO. The last technical option is the dual-output processing of the signal as in G9 II or Sony A7V, when a lower gain is applied on the signal in highlights vs the signal in the shadows.
I think that the OM-1 has a lot of potential, however, the success of this system is going to depend mostly on future improvements in sensor design. For future success, OM may want to have a close collaboration with a company like Sony that makes sensors. If Sony asked me (purely theoretically), I would have strongly suggested them to acquire OM and invest in this system instead of the APS-C. The interesting computational features that OM cameras offer are welcome as well. If OM could implement in-camera raw denoising as efficient as that in DxO DeepPRIME, with in-camera output to denoised DNG - that would be great.