Thanks for the quick response!
Both are most recent plugins versions as fas as I’m aware - Krakatoa MX 2.6.1 and Frost MX 2.0.10, Max 2017 SP1.
It is not recalculating the mesh and the “update” is much faster, around 1-2 seconds while Frost reports 30%, 40%, 50% progress quite quickly and then gets back to normal.
There’s one PRT Surface object which holds around 20 objects, however they’re quite highres, around 40 million polygons and generates a massive point cloud - I don’t have a number right now, sorry.
I can easily work with any other object not being a particle source for the PRT Surface object but as soon as it’s one of these it’s producing a lag upon any action, selecting, deselecting, entering subobject mode etc. This happens even if all the source objects, the PRT Surface object and the Frost mesh are hidden. I remember having a similar problem with earlier versions in Max 2016, not sure if it’s related.