Buttons, even NullAction()'d, even offscreen (in a viewport), slow the UI down to a crawl in high numbers (more than about 100 on my system)
Solution:
Minimize the instantiation of buttons where possible
Convert major viewports to vpgrids. Vpgrids natively optimize items by not rendering children that are not visible
Note: The vpgrid scrollbar will attempt to preload non-visible content when gaining focus. Thus, slowdown will still happen if there is an insane number of children - but not until it's unavoidable
Buttons, even NullAction()'d, even offscreen (in a viewport), slow the UI down to a crawl in high numbers (more than about 100 on my system)
Solution:
Note: The vpgrid scrollbar will attempt to preload non-visible content when gaining focus. Thus, slowdown will still happen if there is an insane number of children - but not until it's unavoidable