Correct, demonstrated crosswind limits are advisory only, however if something goes wrong when above those limits the pilot trying to be a test pilot will be fully and solely responsible for the outcome. However even in olden manuals there were usually real limitations for stuff like autoland / CAT III.
However nowadays most manuals contain fixed crosswind limits which indeed are a limitation and not an advisory. QAR-Analysis will makes sure that busting those limits will be found out and depending on the rules in the relevant country/company will lead to a nice chat in the safety department, retraining or suspension.