Outside of having what amounts to a couple of shells and removable seats that can be mounted to the box (and a removable rear panel from the cab to join them to create a single 'interior' when using them), the majority of their BTO options are really basic module swaps where most of the complexity comes from managing inventory of the various SKUs than anything else.
As somebody with a '99 Ford Ranger, the Slate is incredibly appealing as nearly every other manufacturer has completely abandoned the compact pickup market; although it has the same issue that the Ford Maverick and Honda Ridgeline do, it's a unibody design. If they actually launch I may end up getting one if they release some BTO options to slot a double-din mount and door-mounted speakers in to handle runs to the hardware store and towing lighter loads on paved roads, but I really wish somebody would do a compact frame-on-body pickup again for those of us that drive poorly maintained dirt roads in forested/mountainous terrain where some body damage (and thus, the cheaper repair costs associated with body-on-frame designs are nice to have) is always lurking around the corner.
[Seriously, I understand the difficulties of batteries and such with EV's and that's likely part of why the Slate is designed this way. But, for people like me who actually need a pickup to do pickup things, not haul groceries, it's frustrating when you're accustomed to being able to replace a side-panel on the box for less than your insurance deductible if something falls on it. And that's without even bringing up the obvious disadvantages when it comes to towing and payload capacity.]