Fork lift batteries are so good though, possibly the best there is and very cost effective. Would just be awkward trying to have a swap system with such bulk and I don't think because this does not exist, that it causes too many problems for business. It surely would have been done by now if it was needed.However I do question way a battery swap system can’t be designed for fork lifts.
When it comes to PV storage, a fork lift battery is probably still the best non-mainstream way to do it (not that home battery storage is even mainstream as such yet). I have read of custom setups where people can run their house for weeks at a time on the forklift battery.