I agree that the way XBetza handles multi-leg moves is not very intuitive. I don't think it is too late to switch to a more intuitive notation, as long as it doesn't allow specification of moves that would not be possible to specify in XBetza. Because then it would be quite easy to just equip the Interactive Diagram (or XBoard) with a simple pre-processor, which just converts the more human-friendly notation to XBetza before interpreting the latter.
E.g. how about writing multi-leg moves always within parentheses, using a hyphen as leg separator, and requiring all atoms should be 'compatible'? Where compatibility means they should either all be multiples of K steps, or of the same oblique leap. The Griffin would then be F(F-fsR), and the pre-processor would act on anything between parentheses, run through the legs to see whether range-toggling is needed. Depending on that it then translates the hyphen to a or ya. So that it ends up with the modifier string yafs, after which it then writes the leading atom F to get the equivalent XBetza. (I guess we could also use square brackets and commas, to stay closer to Betza's original suggestion: F[F,fsR].)
As to your specific questions: the Snake is easy: vWvyafsW. This is just the Manticore with all its moves prefixed with a v. The Ship, however is hard. This is not so much the fault of the notation, but caused by the fact that moves with different initial steps bend in different directions, and you have to indicate which (while for the Snake all moves bent in both directions). The only way to do it is to separate the left-bending from the right-bending move, i.e. the diagonal from the anti-diagonal first steps. This in itself is cumbersome, as there are no shorthands like v or s for diametrically opposed diagonal moves. So you have to write out all directions, and being diagonals, each direction requires two letters. E.g. a Ferz moving along an anti-diagonal is flbrF, and in the Ship you want those to bend to the right (i.e. fr) in the next leg. So you get flbryafrF for these two paths. And then you have to write the other two paths in the same way, changing all l into r and vice versa. This is how I did it in my Diagram for Tamerlane II. (Note that flbr[F,frR] as it would look in the proposed more intuitive system would not be much less cumbersome...)
I agree that the way XBetza handles multi-leg moves is not very intuitive. I don't think it is too late to switch to a more intuitive notation, as long as it doesn't allow specification of moves that would not be possible to specify in XBetza. Because then it would be quite easy to just equip the Interactive Diagram (or XBoard) with a simple pre-processor, which just converts the more human-friendly notation to XBetza before interpreting the latter.
E.g. how about writing multi-leg moves always within parentheses, using a hyphen as leg separator, and requiring all atoms should be 'compatible'? Where compatibility means they should either all be multiples of K steps, or of the same oblique leap. The Griffin would then be F(F-fsR), and the pre-processor would act on anything between parentheses, run through the legs to see whether range-toggling is needed. Depending on that it then translates the hyphen to a or ya. So that it ends up with the modifier string yafs, after which it then writes the leading atom F to get the equivalent XBetza. (I guess we could also use square brackets and commas, to stay closer to Betza's original suggestion: F[F,fsR].)
As to your specific questions: the Snake is easy: vWvyafsW. This is just the Manticore with all its moves prefixed with a v. The Ship, however is hard. This is not so much the fault of the notation, but caused by the fact that moves with different initial steps bend in different directions, and you have to indicate which (while for the Snake all moves bent in both directions). The only way to do it is to separate the left-bending from the right-bending move, i.e. the diagonal from the anti-diagonal first steps. This in itself is cumbersome, as there are no shorthands like v or s for diametrically opposed diagonal moves. So you have to write out all directions, and being diagonals, each direction requires two letters. E.g. a Ferz moving along an anti-diagonal is flbrF, and in the Ship you want those to bend to the right (i.e. fr) in the next leg. So you get flbryafrF for these two paths. And then you have to write the other two paths in the same way, changing all l into r and vice versa. This is how I did it in my Diagram for Tamerlane II. (Note that flbr[F,frR] as it would look in the proposed more intuitive system would not be much less cumbersome...)