I was eager to know how to modelling latent interactions for structural equation models in lavaan. There is this lavaan google group https://groups.google.com/forum/#!forum/lavaan where one can find a lot of comments by searching for “latent interactions”.  Basicly there is one paper from Mash (2004) and one from Lin (2010) explaining the methods in detail. Inspired by https://rpubs.com/mkearney/103098 (data not available) I compiled a script summarizing the methods developed by Marsh (2004) and Lin (2010) by using the HolzingerSwineford1939 data.

See  http://rpubs.com/candrea/latintsem .