The fact that somebody on board literally has a physical copy of Self-Improvement for Isekai Self-Inserts is evidence against this plane being in a trope-abiding isekai scenario, really.  Having your character take a physical copy of Self-Improvement for Isekai Self-Inserts with them on the isekai, and not need to remember any of it, would just be odd.

To be clear, there's plenty of stories in dath ilan that don't obey all the standard tropes, and are, on quite deliberate purpose, odd.  Thellim is just saying that, if they find themselves in another world with a physical copy of Self-Improvement for Isekai Self-Inserts and no need to use their memories about anything inside, they should keep watch for strange inversions of other tropes too.

The fact that somebody on board literally has a physical copy of Self-Improvement for Isekai Self-Inserts is evidence against this plane being in a trope-abiding isekai scenario, really.  Having your character take a physical copy of Self-Improvement for Isekai Self-Inserts with them on the isekai, and not need to remember any of it, would just be odd.

To be clear, there's plenty of stories in dath ilan that don't obey all the standard tropes, and are, on quite deliberate purpose, odd.  Thellim is just saying that, if they find themselves in another world with a physical copy of Self-Improvement for Isekai Self-Inserts and no need to remember any material it covers, they should keep watch for strange inversions of other tropes too.