If you change the actual logic ladder or code in a programmable controller, a hot download to the BCU works fine. However, you must then do a separate "Download Application" to the individual controller itself.
If you need the or the official feature list for your specific controller model number, let me know and I can direct you to the right section.
: Requires Microsoft Visual C++ Redistributable (typically 14.2) for legacy USB drivers. Note on Downloads