My reading of it is that the PSL allows you to permanently transfer it to friends or family. "Bequeath" also implies "...on your death"!
You can also sell it using the club's transfer page. Such a page does exist, but last time I looked, there were none for sale.
Like Bozza, having looked closer, I can see nothing that allows holders to transfer it on a game by game basis...
This page is dated March 2014, so I have no idea whether the single seat listed is current, but on a static page, or whether the whole page itself is stale:
https://www.brightonandhovealbion.com/news/2014/march/private-seat-licenses/