Hidding groups in prespective with Technical/Pen view activated takes ages to complete.
I suspect this is due to the detail in the model you’re using. Send it to firstname.lastname@example.org and I can check it out too for comparison. Technical modes have to calculate hiddens lines so hiding some geometry will require a recalculation. Pen and Artistic are variations of Technical.
If you find the same model and action was much faster in a previous build please let me know too.
hide command freeze (model1):
group command freeze (model2):
tested on iMac27 late 2009 a rMBP 15 mid 2014,
/Beach ball is missing in quicktime screen recordings/