Under which circumstances a trading venue may cancel, vary or correct a transaction?

Article 1(2)(d) of RTS 8 establishes that quotes shall be deemed to have competitive prices where they are posted at or within the maximum bid-ask range set by the trading venue. Does this mean that trading venues have to have published maximum bid-ask ranges for all instruments traded on their venues or only for the instruments on which they have a market making scheme in place?

In terms of the Order to Trade Ratio (OTR), how should a trading venue tackle cases where a market participant has executed no trades after the submission of a high number of orders?

Could trading venues set out different OTRs for different types of market participants (e.g. firms engaged in a market making scheme)?

Under Article 3(2)(a) of Commission Delegated Regulation (EU) 2017/580 (RTS 24), there is a requirement to flag orders submitted to a trading venue “as part of a market making strategy pursuant to Articles 17 and 48 of [MiFID II]”. Should a firm start flagging orders when it decides to submit orders with a view to make markets in a particular instrument, or only when it concludes a formal agreement with the trading venue subsequent to triggering such an obligation under Article 1 of Commission Delegated Regulation (EU) 2017/578 (RTS 8)?