Could start_session() be postponed to first add to cart action?

Hi,

Trying to set up MarketPress on a site running on Nginx with FastCGI Cache, I find that nothing is cached due to the fact that MarketPress does start_session() right from the MP class __construct method.

Would it be possible to postpone this start_session() stuff to the moment a visitor actually adds something to cart or visits his download page or has a cookie from a previous purchase session... Or anywhere else where a session is actually needed. Just not for every anonymous visitor.

As it is now, with MarketPress activated network wide, it defeats the whole server cache for every site even if there are no products configured

I'm willing to spend time on testing and coding any possible solution or even work-around.

Thanks for any thoughts on this