Hi @ViktorJr,
As you said, 9ES2 support creating VLANIF interface on the card itself, while 8FE1GE cannot. The difference doesn’t mean that 8FE1GE card cannot connect devices in different network.
Actually, when the card 8FE1GE inserted, and the vlanif interface created, the vlanif interface is created on the router itself, rather than on the card. In other words, you might consider the 8FE1GE card as an addon of the router, while 9ES2 is a small router which coorpate with the router which inserting the card.