I do not think it is SÄPO you need to worry about, it is FRA who does most spying.

SÄPO would comply with fourteen eyes directives, no? Is that not what 14 eyes membership implies?

No, that isn't what membership implies. It is a cooperation and data sharing agreement, it doesn't unify countries intelligence agencies across borders.

For example GE makes engines for Boeing airplanes. They may have a cooperative agreement and mutual non-disclosure agreements that allow engineers and designers to share engine attachment and airframe details freely, but that doesn't mean GE employees have access to information on the radio headsets.