There isn't a PHEV version of Maverick yet, but I'm sure there will be since the platform is shared with Ford Escape which has a PHEV. Notably, the PHEV Escape loses storage space compared to its hybrid and pure combustion siblings. PHEVs need batteries an order of magnitude bigger in size and capacity compared to regular hybrids and they need to go somewhere.

Using skateboard batteries for PHEV would help mitigate the packaging issues for PHEVs, but then you're still stuck hauling around a combustion engine and all the design compromises that entails like long, tall hoods filled with components.

Skateboard batteries mean deep, expensive changes to platforms, the kind automakers only do every decode or so. With the cost of batteries plummeting and emissions rules like EU7 coming, most companies have chosen to focus their development dollars on pure EVs and cheaply retrofit their PHEVs on to existing ICE platforms.