In the UK community colleges are not part of the higher education system and the US equivalent of a small liberal arts colleges essentially do not exist. That means the vast majority of UK universities hire for "research excellence" and hiring committees are really only interested in if you can teach a needed module and that you will not be awful. The PGCE, unlike the PGCHE, would not satisfy any university requirements and therefore I don't think hiring committees would consider it at all.
As for the PGCHE, while many universities require new members of academic staff to obtain one, The universities that I am familiar with offer the PGCHE curriculum in house via the School of Education. Since it is presented to new staff as a hoop to jump through, I know of no one outside of university administrators and schools of education that think the PGCHE, in any form, is of value. Further, while I have seen many job adverts where a PGCHE is a "desirable" qualification, I have never seen one where it is "essential". During hiring, we briefly consider the presence/absence of a PGCHE, but never more than that.
Overall, I would say that the PGCE is useless for getting a job and the PGCHE is only marginally more valuable for being hired. As a PGCHE is. Requirement once you have the job, it may be beneficial in that it would make your first year, or two, easier since it is one less thing to do while you are drowning in new teaching, admin, and setting up a research agenda. The disadvantage of this is the PGCHE course was one place where I met new faculty members outside my school.