The article you posted seems to acknowledge the difference in injection frequency.
I believe that difference is justified by subQ being less painful. That is fine, but I wouldn’t attribute the results to the subQ. I would say it is because of injection frequency, and subQ may make upping the injection frequency easier / less painful.
I think you could make the argument that 80 mg IM twice a week will on average result in trough levels similar to 100 mg IM once a week. @tareload does this add up?
FWIW, I would rank my injection spots from least painful to most painful as IM Lats, SubQ in belly fat, IM delts, then IM quads. The IM quads was by far the worst. IM delt and SubQ in belly fat were close. IM lats has been by far the best spot for me. I have not once gotten pip there in about a year of EOD IM shots.