Jim Beckel was my trombone teacher in college. A great guy! His harp parts are usually not very challenging. He generally has the harp double the bells or xylo, his glisses are spelled out, and occasionally he has fast passages that are rhythmic and repetitive so once you learn the pattern, you are set. I have never played the Toccata but I have played many of his other works. They are very brass oriented and if there has been a “solo” it generally consists of arpeggiated 8th notes that fall naturally in the fingers.
I hope this helps.