flbryafrFfrblyaflF: doesn't work. It skips the F-square
That is correct. But then you simply add it explicitly: FflbryafrFfrblyaflF.
All the bent trajectories you can specify with XBetza skip the first square (or actually the entire first leg if it is more than a single square, or even all non-final legs if they have more than two legs). All legs mentioned in a description are compulsary, and must contain at least one step if they are sliding.
This was a choice; it could have been defined such that slider continuation legs can make 0 to infinite steps, rather than 1 to infinite (like the initial or only leg can). But what would you do then for a piece where you don't want that? E.g. a Griffon that cannot move to the F squares, even though it can be blocked there? It is much easier to add the F moves to a piece that not naturally has those, than it would be to prevent it from stopping on the first square of its path. So asR is a hook mover that must turn a corner, and cannot move like a simple Rook. If you would want it to move as a simple Rook as well, as the Hook Mover from the large Shogi variants can, just write RasR.
That is correct. But then you simply add it explicitly: FflbryafrFfrblyaflF.
All the bent trajectories you can specify with XBetza skip the first square (or actually the entire first leg if it is more than a single square, or even all non-final legs if they have more than two legs). All legs mentioned in a description are compulsary, and must contain at least one step if they are sliding.
This was a choice; it could have been defined such that slider continuation legs can make 0 to infinite steps, rather than 1 to infinite (like the initial or only leg can). But what would you do then for a piece where you don't want that? E.g. a Griffon that cannot move to the F squares, even though it can be blocked there? It is much easier to add the F moves to a piece that not naturally has those, than it would be to prevent it from stopping on the first square of its path. So asR is a hook mover that must turn a corner, and cannot move like a simple Rook. If you would want it to move as a simple Rook as well, as the Hook Mover from the large Shogi variants can, just write RasR.