Mamdani is useful to us.

When he does shit we like and it's effective, we can highlight the effectiveness of social programs and our other policy objectives.

When he does shit we like and is hamstrung by the bourgeois system he operates inside, we can highlight how democratic socialism will always be hamstrung in this way and that demsocs will never be able to fully oppose capital.

When he does shit we don't like, we can highlight how demsocs will always trend towards capitulation to capital in attempts to be "pragmatic" or bolster their position within the bourgeois system.

Obviously, no one here should believe in him or demsoc entryism, but we can and should laud him in ways useful to us. We should defend him against attacks that also fall on us. We should denounce demsocery, entryism, and his capitulations to capital.

Figure out your audience and operate accordingly.