Adding my support to this.... Ideally config on an event by event basis (ie In the checkout of THIS event, allow the option to register for others) - but certainly a general on / off option if nothing else - As great as it is, the cart system simply won't suit every event in some sites (like mine )
For those that don't know... the known cart issues have been resolved in recent updates... but with the new 2.7.0i released today, there is a new config parameter so you can enable/disable the cart completely. Thanks.