I spent a reasonable number the years in airlines that recruited straight out of GA and it was always the pilots without a proper grasp of the IFR environment that scrubbed out of training, or if lucky they battled on as 'strugglers'.
S/E IFR was starting to become more of a thing back then and we changed our recruiting accordingly without the lack of multi time proving any sort of hinderance.
Not every operator moves with the times unfortunately for the OP.
Oh and not one person in those years ever came undone over thier turbine engine handling skills (types pre-fadec). Every time it was IFR ability was the issue.