I have no issue in principle with setting up a liaison. But, I would caution that we have a good (and realistic) understanding of what we are likely to achieve, how much work is involved, how important to industry OMA really is, etc., before agreeing. This really means someone from the side needs to have a pretty good handle on how the OMA works, what its mission is, some of its internal dynamics, etc. Even then, it may be hard to predict where things go.
3gpp is an example where I think having the formal liaison relationship has generally worked and been helpful.
For 3gpp2, I'd say it's not really worked.