Its not the solution at all though. The crux is that two absolutes were stated as insights, and there is a case where only one can be true.
-There is no peace in emptiness, no content in stillness. Stagnation is death; act, change, move, think, and grow until the very end.
-One person's desires cannot alone make a home nor a family.
We chose to damage the former and assauge the latter by making the promise, by setting a restraint upon our growth, the existence of the promise itself is now the heart demon, because we've now dragged more insights onto the table:
-Sincerity is the measure by which the worthiness of the self and ones guests should be measured.
The heart demon is no longer about the desires of our family. That problem is behind us when we made the promise, though Zhengui's own self confidence issues are not gone.
We're now facing a heart demon consisting of a catch-22 - by following the promise, we are sincere and worthy but we imposed stagnation upon ourselves, we can no longer grow in ways which require self sacrifice or leaving family behind. By breaking the promise, we diminish our worth and we'd also have harmed our family, which our base domain, TRF and FVM agree are very important.
Fundamentally the heart demon comes from picking 4 different determinator insights and then being pincered between them when they diverge. The promise sparked it, but keeping the promise brings us no closer to a solution, nor does breaking the promise.
This can only be resolved by having the promise either retracted, adapting such that the promise no longer hinders growth, or expanding definitions such that a loss in one area can be made up in another.