The way I would put it is — indeed there are no “boundaries” in actuality. The feeling of ‘me’ the feeling-being existing , creates an artificial perceived boundary / separation between ‘me’ and everything else.
HOWEVER, it’s not the case that actually ‘I’ as feeling-being exist , and there is no boundary between ‘me’/‘my’ feelings and the rest of the universe.
RATHER, what one finds is that ‘I’ the feeling-being am that very illusory boundary in and of itself. ‘I’ am the separation in and of itself. ‘I’ am a felt yet not factual separation.
When the lack of boundaries is experienced as an actuality - simultaneously one is experiencing a PCE and ‘I’ am already absent (and seen to not have really existed). (And it also becomes clear what “exists” refers to in this case ).
And conversely when a PCE is what is eventuating one finds that there are in fact no boundaries being experienced - ending of ‘me’ is the ending of ‘boundaries’.
So it works both ways, it is an “if and only if”.
The mistake was thinking there is a ‘me’ that is then separate from the universe via a boundary, ie thinking there’s 3 things: ‘me’, boundary, universe.
Actually ‘I’ am the boundary, so it’s only two things: ‘me’=boundary and universe.
And only one of them is actual !
If one were to have done such a thing as to be experiencing one’s feelings & emotions as not having any boundary between them and the universe, and not seeing that those feelings/emotions/me in and of itself is/are an illusory boundary … essentially one would be projecting one’s ‘self’ to cover the entire universe, which would give the lived illusion of no separation, but one would in fact continue ‘being’ that very separation, still impossibly separate from actuality, still covering up that pristine purity with one’s ‘being’…