does mikveh before shabbos require kavanah?

The gemara (Chulin 31) writes that tevila in mikveh for kodhsim requires kavanah but for chulin it does not (discussed this back in Feb – see here). The Sidduro shel Shabbos writes that for those who follow the minhag to be toivel in mikveh before Shabbos (I don't), kavanah is required; nothing is accomplished by doing a “ma’aseh kof” and just dunking without any intent. The tevilah should bring to mind 1) that one is divesting oneself from activity of chol, and 2) that one is accepting the kedushas Shabbos (according to R’ Chaim Vital two tevilos are actually required, one for each goal).