Good idea,
I was just recently gifted a variac and isolation transformer....
On the question of stumbling... its a bit like tango...got to know the moves... it is not a contortionist act.
The keyboard has two groups of keys F1, F2, F3
and four arrows and Enter key
I knew the code for setup function in my case
F2 . left arrow, up arrow , down arrow
A two handed two fingered salute.
So in similar vein the Tune code turned out to be F1 left arrow down arrow right arrow... just like a steamy tango