PLS is now available in PALM. Use it in the same way as you'd use CCA, except that, instead of "-mv cca k", you'd use "-mv pls k". It will output and run the statistic on the correlation between the k-th pair of vector scores (akin to the k-th canonical correlation for CCA). If k is omitted, the default is 1.
Please note this is a new feature and not much tested. If you find a bug or anything that looks strange, please send an email.
Hope it helps!
All the best,