Can X3-ULTRA achieve the whole homeloads without matebox or EPS box?

It depends on the total power rate of your homeloads, if it is lower than the inverter EPS port rated power, then you can connect all the loads to inverter EPS port to achieve the whole homeloads without EPS box or matebox, if it is higher than EPS port rated power, then EPS box or matebox advanced version is needed to achieve the whole homeloads. Also please be advised that X3-ULTRA is not compatiable with matebox.