Pros and Cons of Starting to Fund in a VEBA/Other H&W Trust

I am working on presenting such pros and cons to a client.  I can think of fairly long list of cons, but the only *pure* pro I can think of is benefit security for the members/participants. 

Anything else I can think of has significant cons working against it.

A taxable entity could get a deduction for contributions, but for medical that is significantly limited and would require an annual determination.

The trust could invest in assets the plan sponsor can't invest in directly, but that's problematic.  I.e., should any plan sponsor do this when the presumably have a core business/mission that they should focus on?  

Funding would lower the GAAP expense for the plan sponsor, but that is offset by the opportunity cost of using the money for something else.

What am I missing as a pro(s)?

There used to be a fairly thorough CCH or Prentice Hall practice guide on VEBAs 501(c)(9) trusts- if I were you I’d look up a couple of those resources as it’s a long essay answer - one pro is an accelerated deduction in certain instances for a few non-traditional benefits