Sindicates or partnerships - Limit to Three members

Just a heads up about something I'm now too familiar with. If you are
considering a partnership in a glider, it is probably wise to limit
the number of people involved to a maximum of 3. I now know that with
4 people, the insurance becomes highly restrictive, unless you pay
significantly more and obtain 'commercial' insurance.
With 3 members, letting any rated friend fly it is no problem. With
4, NO ONE ELSE can touch the stick. There are ways to add pilots, but
they involve coordination with the insurer, and additional money.
Just FYI.