Using the CORE client there is extra session mode called PRE_ACKNOWLEDGE. In the case of Qpid JMS

if you set presettle for consumers then in AMQP land the broker sends the messages as settled meaning that the client doesn't need to send back a response as the broker has already forgotten about the message
so yes, with presettle it doesn't matter what the ack mode is, the client can't and won't send back a disposition (ack)

However,

This seems to be global for the connection factory/connection, where as with core, because you can set it as a session ack mode (also noted can make it global via CF settings), it doesn't have to be global, it can be just for that session, as such a connection can share both sessions with need pre-ack and sessions that need other modes.

I guess whats being asked for is the ability to set it like in CORE at a session level from JMS, so that the AMQP JMS client is at parity with CORE client. Ideally with the same session ack mode int, so that CF can be swapped between CORE and AMQP.