I've been using DisplayLink and the Startech adapter for 6 months and it's been rock solid. There is also a Dell hub in the middle as I could never get it working without.

Flow is as follows: Macbook -> USB-C -> Dell USB-C hub -> USB-A/B -> Dell monitor (USB hub) -> Startech adapter (USB A) -> 2x Dell Monitor DisplayPort.

FWIW I have 2 Dell 27 1080p both aligned portrait with a MBAir M2 on the side.

As for lag I haven't really noticed or perhaps I've got used to it... I do however use both screens for Teams video calls and it's pretty smooth quality.