Been there. Our Roadster's front crossmember had spidery cracks, too. After some welding, grinding, and paint, it looked a lot better. You'd have to know what you were looking for to know there had ever been a problem. Anyway, the weight of the engine sits on the spring steel bracket that bridges the hole.
Golden?
No. The brass gromet positions the engine. My crossmember still had too big a hole.
So, I installed a Float A Motor front motor mount.
(Hey, I hear that hissing and clucking. Cut it out ladies ... )
I do consider it a temporary fix and I've already purchased a really nice frame to set the car on ... next winter. But the "temporary" fix is ready for three or four thousand miles' fun THIS SUMMER.