Have you noticed an increase in species-level Sinea identifications? The new mobile app (in contrast to the website) now often gives species-level top recommendations when it is very confident (see this forum post).
When I use the website CV on my recent observation of a later instar Sinea nymph, it says it’s “pretty sure” of the genus and then gives the two species as suggestions. However, using the iOS app, we get this:
This seems like overconfidence if, as you say, nymphs of these two species are equally spiny and can’t be identified to species.