Another posed shot of chilled specimen shows some details of the pronotum and head that were not visible in other photos.

In this photo, one can just see some mouthparts sticking out from the head. These were very prominent in the active insect, and "mouthparts visible from above" is one of the characters for the genus Calochromus mentioned in Dillon. (1) However this appears to be Eropterus--see comments by Phil Harpootlian and references in guide page.

On this photo, note especially how the pronotum (thorax) is divided into cells. This is a character of Platycis and Eropterus given by Arnett et al., p. 213 (2). The former has strong ridges, the latter has weak ridges, so it appears to match Europterus. (I'm just folowing along the key here, not doing it from scratch.)
--See comments on ID.
Image updated 8/1/22.