Now you know WHY they named your guitar "The Soloist". It was specifically designed for full access to the top of the neck when soloing. My BC Rich, Hamers, PRS are the same way - no problem to play on the highest frets.
But, a Les Paul Custom was my main guitar for many years - it still gets some play time. Here is the trick to playing above the 12th fret on an LP :
When I play high on the neck of a Les Paul (or, a little higher on a Strat) I don't keep my thumb behind the neck - I just use finger pressure, counterbalanced with my right forearm. The strings are skinny enough to bend that 22nd fret D to an E, F, maybe a G (depending on string gauge and individual guitar).