I am planning on buying FXSA-A ducted units in EU. The compatible WiFi module listed is BRP069C51.
This apparently works with Daikin Onecta app.
But does it work locally with Home Assistant?
Or maybe is there an older WiFi module that is better suited for HASSIO and is compatible with FXSA-A?
See: https://www.home-assistant.io/integrations/daikin/#supported-hardware
In short "no". There is no local API. It may work with the cloud but the number of daily requests to the API is extremely limited.
Either use a faikin/faikout adaptor or P1P2MQTT adaptor instead of the BRP069C51 (I think your heatpump is compatible with the P1P2MQTT, not the faikout).
Or choose a different brand and let the company know why you changed your mind regarding the purchase (no local API).