Maybe I am not yet good enough with all the biblatex stuff and I don't understand your code correctly, but it looks strange to me that there is some code right after the true case of \ifbool{bbx@publimedium} is finished, but before the empty false case with {}%-keep-blank starts...
Hi! During a disscussion (see https://github.com/michal-h21/biblatex-iso690/issues/116) of the biblatex iso 690 style which I contribute to, @moewew pointed me to your style so that I had a quick glance at it.
Maybe I am not yet good enough with all the biblatex stuff and I don't understand your code correctly, but it looks strange to me that there is some code right after the
truecase of\ifbool{bbx@publimedium}is finished, but before the emptyfalsecase with{}%-keep-blankstarts...