- Close other channels' editor windows before attaching a new one (Option B)
- needsReload()/setReloading() guard: skip processAudioBlock during
terminate+reload teardown to avoid UAF/hang when reopening GUI
- Wait for editor registry cleanup (5s timeout) before creating window
- InstrumentEngineManager::assign: destroy replaced instrument OUTSIDE mu_
(VST3 terminate/removed can block -> audio loop stall -> bridge Not
Responding, transport stop hangs, notes never off)
- main.cpp LOAD job: DestroyWindow any open editor window of the channel
before assign (replace VSTi -> SF2 with editor alive hung in removed())
- Vst3Instrument: reload() fresh plugin instance on second openGUI after
close (Nexus etc. hang at view->attached() twice on same component)