Feature request: limiting isolation level choices

Hello,

Apologies if this is the wrong place to make such a request.

It would be useful to have the ability to prevent clients from setting whatever isolation levels they choose. Specifically, it would be desirable to enforce SERIALIZABLE for all transactions since the serializable guarantee only holds if other transactions also use the isolation level.

EdgeDB which is built on Postgres only allows the SERIALIZABLE isolation level, for example.

Thanks