I will have a look at the programing and see if I can put a switch on the GUI or a keyswitch in somewhere but for now you can swap the acoustic mic samples for the EQ'ed samples and use the pickup select/blend knob.
https://www.dropbox.com/s/msd6rbvcjxf3tl7/ShinyGuitar-acoustic2.rar?dl=1Click No Thanks Continue at bottom to skip loginRename Samples/acoustic > acoustic - original
now extract the acoustic2.rar acoustic folder.
In the GUI folder backup main.xml and you can rename the knob.