https://www.etsy.com/uk/listing/1724988301/lian-li-fan-shroud-ducts-for-o11d-o11d
This one looks tailor-made for the CPU intake.
https://www.etsy.com/uk/listing/4370532434/pc-fan-heat-deflector-fan-airflow
And this is what I meant about routing the CPU heat towards the upper exhaust. That would hopefully keep all the airflow going from bottom to top, yeah?
Thanks for the sanity check. I'm really excited about this idea, appreciate all your advice!