I've searched far and wide, I called about 6-8 different insurance companies, including Progressive, and I can't find anyone with a good answer for this one. As far as I've been able to find, if you convert your van into a camper, **no** insurance company will honor a claim, either for your vehicle or the other vehicle. Apparently this kicks in as soon as you make a "permanent" change, which to them includes securing a bed, kitchen, or any other furniture to the van.
If you omit the camper/conversion/DIY part, you can *get* the insurance, but once you file a claim and they come look at it, they'll say it's not covered, and probably cancel your whole policy. And this goes for comprehensive, collision, liability, RV, and even "declared amount" insurance for the few who offer that.
The only time they'll cover anything in a campervan is if the conversion was done "professionally", and nobody seems able to tell me what defines a professional conversion nor how to become professionally certified, or if that's even a thing. But they've all said specifically that if you do your conversion yourself, claims won't be honored. If you tell them about it, they won't even give you a policy.
None of them even asked me about an RV title. They don't care. Plus an RV title seems to require a built-in/permanent bed and fridge, and built-in and plumbed sink and toilet. These things make it more complicated and take up more space, and they couldn't define what it takes to be considered built in / permanent.
Does anyone have any answer other than this? Has anyone actually filed a claim on a DIY campervan?