Once in a while I notice certain VSTs don’t account for the host software’s sampling rate, and calculate their oscillations/etc under a hard-coded assumption that the host software uses 44100hz – for example, older versions of ZynAddSubFX exhibited this problem. So if Renoise uses a different native sampling rate other than 44100hz, the VST produces off-key sounds.
For an individual Instrument which uses such VST plugins, an optional setting that would let the user select a forced VST-specific sampling rate, and then Renoise would natively upscale/downscale the outputted sound to transparently sound natural under Renoise’s native sampling rate, would be very helpful.