I don't think DOIs would help, but I'm not a GScholar expert or even regular user. I know that some journals (e.g. JOSS (npub103g…0rvv)) have had or are having issues with getting papers to be deterministically found and listed by GS crawls (https://github.com/openjournals/joss/issues/130).
DOIs (and good DOI metadata) are, however, of great use independently of any specific platform...