Thefekemaven, in Daas Noteh Reb Chaim is very strong NOT to wear the techeies. He quotes the Medrash there too. I’m not sure whichbRishonim you are referring to, but he says the Maharil etc. Is not a proof against this Medrash, and the Medrash means we won’t have it until Moshiach.
The shoel seems to be pressing the issue asking what could be wrong with wearing it just in case. He answers very strongly not to wear it. He also quotes the Chazon Ish also saying not to wear it, the Beis Halevi too. And in the footnotes he brings Reb Dovid Soleveichik that according to the Rambam, if it’s not the real thing, you are not yotzei the mitzvah of tzizis at all.