Yes, all three expanders should work as they are supported by RPLCD library. I have only cheap PCF8574T I2C LCD, so I’m glad that other boards will be tested.
The small adapter should replace dupont cables in the future. I’m planning to rework this ospi enclosure and make holes for few types of LCDs.
PS: Yes you right. Probably this is going to be permanent solution… 🙂