Do please report back! The monastery is so historically significant, and once rivalled Ronceveaux for delivery of crucial refuge to those arriving from the Bordeaux region and preparing to go over the pass to Elizondo et al...
I understand there is a good museum (it was closed when I was there in May), and I'd love to know if it does have a clear sense of pilgrim purpose.
My experience of the Baztan in spring was that: the scenery is lovely, and hospitality can be had for a price, but the importance of the route as "pilgrimage" has been largely forgotten. Things are very expensive (I worry about people without the means available to get themselves out of a pickle if needed; see the price of the hotel posted by
@peregrina2000 -- it's an accurate reflection of similar along the way).
Beware also the "albergue" in Elizondo. The current operators seem to use it more as a truck-stop than an albergue, ad do not have a concept of "pilgrimage". (FN below)
They do not, in fact, provide laundry machines (which is fine, but there is also nowhere to hand-wash or to hang clothes). If it is raining, expect water to come in the ceiling... the food is OK in the restaurant on the main floor (I'm not picky when hungry). When I needed a taxi to avoid a hail storm on the following day and my e-SIM/whatsapp limitations meant I could not *phone* for a taxi, the staff were unhelpful... they told me they would call for me, and I waited... until at 11am when a promised taxi had not arrived, I decided to try to find one by myself on the street. I went into town, found a very nice hotelier getting ready to open for the day and he phoned a cab for me that arrived in 5 minutes and took me over the pass, through the pouring rain and avoiding hail.
FN: I have stayed in some fine truck-stops on different caminos... on the Primitivo at Pinaro, and on my first day on the Portuguese, about 26 Km after Coimbra. Those locations were very familiar with and welcoming to people on camino (and were well-priced and clean, with everything one might need).