+1
Groove Agent is a realey great drum machine - I love it
And yes please make it resizable!
You’re the inventor (Steinberg) of VST and VST3 has the option to resize the plugin as you mention in your VST3 specs:
Resizable edit windows
VST3 introduces a new approach to plug-in GUIs though window resizing, allowing for extremely flexible use of valuable screen space.
Thanks Steinis to make it come true 
cheers
sonicwarp