you are right, Steffen, the original RE-201, as other tape echoes, do have a tap button. But let us not exaggerate the authenticity of an emulation. We are still within a digital console of the new millennium. So let us add som comfort and allow the user to use a tap button to adjust the speed of the virtual tape. For all those users, which want to adjust the virtual RE-201 with all it vintage charm this tap button may not even be visible on the screen. Exact that is done for the WING Tape echo emulation, for instance.
a +1 from my side.