@Johnny_TVL the now ~650K BNT is coming from trading fees. Currently 90% of trading fees on v3 - which are normally earned by LPs - are being used to buy BNT and this BNT is accumulating in the v3 fee wallet here: Bancor: Bancor Network V3 | Address 0xeEF417e1D5CC832e619ae18D2F140De2999dD4fB | Etherscan
More info on how this works can be found in the original v3 proposal BIP15 - excerpt below:
Bancor Vortex
The function of the Bancor Vortex remains unchanged in the new release; however, its specific behavior is modified to be more efficient. Rather than collecting a wide variety of token types, the Vortex on Bancor 3 will collect BNT exclusively; fees earned in TKN are swapped immediately for BNT. Therefore, triggering the Vortex results in a single swap of BNT for vBNT directly, rather than a myriad of swaps across numerous TKN pools for BNT as a first step. This simplified arrangement has consequences both for the effective value burned, and an improved gas efficiency overall.
Re changing the tokenomics so that BNT is bought and directly burned on each swap, this indeed could be interesting, and burning BNT directly from the fee wallet is a potential precursor to that adjustment.