What Home Assistant does well
It runs at home, it is free and open source, and community integrations read a Deye inverter through its Solarman logger on your network.
Predbat plans battery charging from a Solcast solar forecast and your tariff, and can do far more if you want it to.
What it asks of you
You need a server, the integrations, a forecast account and your own settings, and you keep them working through updates. When something stops, you find out why.
What Solsidus does instead
The box arrives ready for your confirmed inverter. It learns your home's use, plans each night from tomorrow's forecast, changes only the battery's night target, reads it back and pauses if a safety check fails.
If you already run Predbat happily, keep it. Solsidus is for homes that want the result without the upkeep.