it's possible to spot such transactions if they violate transaction forwarding rules (aka standardness rules) but not consensus rules. for example, a transaction greater than 100kB is not standard but still valid.
Excited to see this new release. Seems to me this would (slightly?) negatively impact query performance for recent data (when the query concerns data is both in O3 and persisted zones), is that the case?
Proof-of-stake coins lack one of proof-of-work coins most important properties: censorship resistance.
In both consensus systems, a censor is someone that has amassed 51% of the currently available stake (in PoW stake is mining machines, in PoS it is outstanding tokens).
In proof-of-work systems, a censor can be unseated by censored parties allocating more capital to mining machines until non-censoring parties own 51% of all machines.
In proof-of-stake systems, it is impossible to unseat a censor: since it owns 51% of tokens, it will also owns 51% of newly minted units in perpetuity (assuming it doesn't stop censoring and doesn't run into issues that would end up slashing some of their stake).
USDT-USD markets are indeed marginal. however, implied USDT price using BTC as a cross shows USDT is valued pretty much at parity with the dollar by the market:
The real figure is more 2.1% (source: https://www.ssa.gov/oact/STATS/table4c6.html)