Up until which application level should one keep supplying a bachelors transcript of records together with the actual certificate?
In addition to field making a difference, there are strong differences between countries. For instance, for my jobs in the US, I never needed to show any of my diplomas; however, I had to supply my transcripts for undergraduate and graduate programs. By contrast, in Germany, job applicants are normally expected to show their entire pedigrees—which means at a minimum the diploma certificates at both the university and high school levels! (I was also expected to produce the transcripts, of course.)

So, the best advice I can give is to follow the expectations of the industry in the region where you are applying. If you have any doubts about what is required, ask the contacts for the position or program.