So, Stan, typically we try to get him out — he doesn’t love to fly — so we try to get him out for his cameos around the same time.
The Wikipedia page about Stan’s cameos is longer than any Marvel Comic ever published.
But Marvel also had a habit of stockpiling Stan cameos; he’d come to the set for a day or two and bang out several of them at once to cut down on his travel.
We are not emotionally prepared for the first MCU movie without Stan in it.