The IGM Economic Experts Panel explores the extent to which economists agree or disagree on major public policy issues. To assess such beliefs they assembled a panel of expert economists. They had something on Modern Monetary Theory recently:

http://www.igmchicago.org/surveys/modern-monetary-theory

Of interest might also be the comments and further links that the economists cite to backup their opinions.

It makes sense as a different way to conceptualise the government's budget constraint - limited by inflation (or the maximum sustainable level of seignorage) rather than an ability to borrow per se.

I just think analysing matters that way won't show that the government can spend a significant amount more than it does today, without higher taxes. There isn't lots of latent productive potential in the economy right now that could be unleashed, if only there were more spending. If that's correct, that makes it a much less interesting idea.

From the Bank of France this week their take:

In the last few years in the U.S. and especially since the publication of Stephanie Kelton’s book, The Deficit Myth (Kelton, 2020) in Europe, the so-called Modern Monetary Theory (MMT) has been gaining prominence in the media and the public. This paper exposes the main proposals of MMT in the light of their doctrinal sources, also confronting them with economic facts and with other currents of economic thought. The first part deals with the approach to money and monetary policy developed by MMT, the second part with its recommendations regarding fiscal policy and aggregate demand management, the third part with the structural policies it advocates, the fourth part with the international aspects of MMT. The fifth part concludes. Overall, it appears that MMT is based on an outdated approach to economics and that the meaning of MMT is a more that of a political manifesto than of a genuine economic theory.