I must say that I find it very difficult to have a rational discussion on what should or should not be included in post counts until the preliminary question of what it is that post count should be regarded as signifying (if indeed it signified anything) has been resolved.

If you take the view that a post count is at best irrelevant and at worst misleading, then surely the rational answer would not be to include OMNI in post counts to prevent perverse effects but rather not to count posts at all. Take away the incentive for post-padding (i.e. post count) and there is no reason why indviduals should post-pad (beyond the initial OMNI elibigility threshold).

It you consider that post counts do matter or if, regardless of your own personal opinion, you consider that a sufficient number of FTers consider that post counts matter so that the 'nuclear' option of having no post count at all is not open, then you need to address the question of what it is that post count signifies.

Here, it seems to me, that there are two main approaches to this. The first one is to regard the post count as a measure of participation in the FT community. We could call this approach the 'badge of honour' approach, in which members of the community which contribute most by their number of posts are recognised by allowing them to wear a badge of honour with a high post count. I can't say that I am terribly sympathetic to this approach which has more than a whiff of, and encourages, male 'mine is bigger than yours' competition about it, but others may see this differently. If this is the significance that you attribute to post counts, then clearly posts in all forums should count. There may be an issue here of insignificant contributions that should be discarded, but it seems to me that the workload this would place on mods,a nd the controversy that it would generate, would far outweigh the benefits that might expected of such strict policing.

Another way to look at post counts is treat them as an indicator of expertise on the subject-matter which is at the heart of FT and its reason for being, viz. FF programs and ancillary travel-related issues. To be sure, post count is an unfaithful friend in this. Some people with a very low post count are extremely knowledgeable and some people with high post counts clearly do not know what they are talking about. That said, when used sensibly together with other elements, most importantly the content of the post and evidence pointing towards a certain background of the indvidual concerned, post counts are not entirely devoid of usefulness. If I ask a question in a forum which I am not familiar with and 5 frequent posters come up with an answer and 5 unfrequent posters come with a different one, all other things being equal, I know which answer I am more likely to regard as probably more reliable.
If we regard post count as an indicator of probable expertise, then clearly posts in OMNI as well as a number of other forums should be discounted. But then, I would probably go along those suggesting that post count in that particular forum is, on the whole, a better indicator than overall post count.

Once we take a view as to what post count should stand for, then we can start to have a look at various solutions (what to include or not include in counts, whether to show exact number of posts of just thresholds, whether to show nothing at all, etc...) and the perverse effect that some solutions might bring with them, in terms of post-padding in particular. We can weigh advantages and disadvantages and we can look at second best solutions, as I very much doubt that a magic bullet that would solve everything and would have no downside is likely to be found. But it seems to me that it would help not to throw the cart before the horse and clarify what it is we seek to achieve by showing post counts first before considering solutions to a problem the full terms of which are not yet defined.

Under any reading, it seems to me that there is at least one useful purpose of post counts, which is to distinguish regular members of the community and newcomers. Clearly, you are not going to react in the same way to a newcomer posting a fairly obvious question that is addressed in the FAQ or sticky at the top of the forum as you would to an established member posting exactly the same question. Whether this requires the actual number of posts or just an 'L' plate type indicator, I am not sure. And beyond that, I am not myself entirely clear yet whether post counts are a good thing or a bad thing. I would probably tend towards the 'indicator of expertise' approach, however imprecise, but I can't say that my views are set in stone on this.