AV has nothing to do with the IRS. If you install any type of IRS outlined alternative vehicle charging station you are entitled to the IRS credit, you just need a receipt for the expenses. There are no "IRS" approved installer requirements, the IRS only cares you paid for it and it is as stated. Nissan wants to avoid all the issues of people messing up their cars so they make all these compatibility statements. This is all so very silly, does anyone think Nissan and EVSE makers won't all play well together on all levels? It is Nissan's goal to have as many compatible stations everywhere they possibly can no matter what the source, they WANT you to have as many public charging options so they can sell cars and eliminate charging objections. Many business will buy from people like Clipper C and others and it will be a STANDARD. There are new residential EVSE products on the way, I know this as a fact and many more will follow. If you want to wait then use the 120 cord and sign the waiver but don't bother telling Nissan what you intend to do it just makes it more complicated. Remember, there will be EVSE stations all over and Nissan FULLY expects people to plug into them if the cord fits and they don't expect people to check the box for a "Nissan" approved sticker. This entire thing is being blown out of proportion, it is a basic charging cord with a standard communication and this is about not stepping on toes at the moment. If the price makes sense form AV, then get it as it will for many. DIY people will find their own solution.
The IRS docs are available online- nothing stipulates an IRS approved installer as expected
Don't expect to see EVSE units in places that won't work on a Leaf, unlikely unless broken
Expect affordable EVSE options in the private market (not funded programs rushing to use the funds to get paid)
Ask AV for their IRS "certified documents" so you know that you will get the credit and they are "approved"- LOL