I feel confused about something.
Even though you've read the prajnaparamita sutra and words like 'form is emptiness, emptiness is form', you say there is a phenomenal world and a transcendent world. But the phenomenal world can't be impermanent if it is not born and doesn't die. Although possibly apocryphal, the sutra of immeasurable meanings has a sentence like the nature of true reality is that appearance and no appearance not apart from each other. That is to say, it seems that the things like Bodhisattvas referenced in the Lotus Sutra may need to be understood with the background training that transcendent wisdom means that the phenomenal world is the transcendent world. It isn't that they don't exist but that Buddha's enlightenment was explained, as you know, to not have been obtaining anything distinct. I take it to mean that enlightenment needs to be in and about the entirety of real life.
It's been said sometimes to be a waste of time to debate whether a certain thing exists or doesn't exist because, for one, a thing cannot be said to exist to anything else in the universe if it is totally isolated, i.e. not been localized by any other system yet, and cannot be entangled with. A controlled experiment could be said to basically mean "one unknown to vary (hopefully)". But entanglement is a reality.
"Anyone who, for even a moment, gives rise to a pure and clear confidence upon hearing these words of the Tathagata, the Tathagata sees and knows that person, and they will attain immeasurable merit because of this understanding."