The developers making apps for Homey Pro do not need to pay the 99e.
For me Z-wave is very stable. Range is not good, but with extender(s) you get along great.
Nowadays zigbee is working good. Same comments than for zwave. The problems in the past are fixed.
I would recommend you to connect Hue devices straight to Homey Pro. That way you get large zigbee mesh.
Never tried HA, but can recommend Homey Pro.
