The current script works by the looking for useliquidthreads:1, converting, then removing the useliquidthreads.

That doesn't work on three WMF wikis (strategywiki, sewikimedia, ptwikibooks), since there it is enabled by default (https://se.wikimedia.org/wiki/Diskussion:Made_up_name%20asdf?uselang=en).

The simplest way I can think to do this is to look for talk pages without useliquidthreads:0 (it's okay if it has useliquidthreads:1), double-check they're enabled (using LqtDispatch) as we already do, convert, remove useliquidthreads:1 (if it's there), then add useliquidthreads:0.

This can be done either by subclassing LiquidThreadsApi\ConversionStrategy and adjusting the entry points, or just always handling both scenarios in the same conversion strategy (probably the latter is better).