Shūnyam is the natural, necessary and inevitable limit of Inquiry [the ‘Reality-Limit’ of the Sūtra].
For to not end the search [Saṃsāra] in the arisen conviction of the absence of a ‘Self’ is to have not awoken to the significance of the absence of a ‘Self’ in the first place.
The Subject is not just the symmetric complement to Object. They are not equal in their significance. Subject is the source of the Subject:Object construction itself. That’s why it’s special. When Subject goes it takes with it its construct.
The analytic convenience of the ‘Subject-Object Divide’ is one unit. The recurring act of an undead Subject is to name an Object that in turn reflexively gives it life. They are mutually supporting modeling artifacts and cannot survive except in partnership. Until Subject exits, you will be endlessly entertained and beguiled with new Objects and newer Names [NamaRupa].
If you can still name an ‘Object’ that corresponds to an absent ‘Subject’, you’re not yet done with ‘You’. And Subject exits, at and only at, True Nothing.
Saṃsāra [literally, a ‘disoriented search’] ends when in sight of Nirvāṇa. And this is as far as you can go; nor are you expected to go any further.
The fundamental question of Philosophy: ‘What is?’ is no longer your question. You know that to still ask it is to have not yet sighted Shūnyam.
‘Show us not the knowledge beyond our capacity; come to us, O Indra‘ [Rig Veda: 1.4.3]
The ‘Limit of Inquiry’? Inquiry with a capital ‘I’. I’m still inquiring as to why my spinach never blanches just right.