it wasn’t pitting again which was the issue, it was the fact they put him into traffic.
wait 1/2 laps longer and he’s passed the ricciardo train and flying in free air.
the minute they put him behind other cars completely destroyed the under cut advantage, that’s why he’s annoyed.
he said himself the tyres were fine to keep pushing, they had zero reasons to pit him that early other than they miscalculated it and fecked it up.
They couldn't wait for the perfect moment as they like everyone else had heard RB's radio message to Max that he should wring out the last of his tires, so they knew he was pitting very soon. If they waited longer then Max could've pitted before/at the same time as Lewis so there was no miscalculation, they simply had to choose between either bringing him in right away or wait for a better window but potentially miss the chance for an undercut altogether.
I think they did the right thing as I'd rather take a bad shot at an undercut than risking not getting the chance at all.