Our building had the original architect as a member of the EC – even though she wasn’t an owner – in the first few years of its existence to help us deal with defects and settling in issues.
But as a general point, who is going to serve a building better – a long-term tenant or an investor owner who may only be interested in the short-term profitability of their investment (which often means “keep levies low until I can sell at a profit – and to Hell with the sinking fund”).
I’d prefer a ban on non-residents serving on ECs rather than non-owners.