Okay, I’ve made a quick test with blueprints.
After pressing G test widget 3000 times is hidden and shown again. This gives small spikes, somewhere around extra 8-10ms lag.
After pressing H test widget 3000 times is removed from parent and then added again. Now spikes are huge. See for yourself:
I don’t if this is only with blueprints but I guess with c++ you’ll get similar results.