I hinge mount. If the conservation community comes around to accept the idea of drymounting again, I can always drymount later. Un-drymounting is possible with the right materials, but it's not easy.
An alternative that is accepted by conservators for albumen prints, which have more of a curl problem than gelatin prints, is starch mounting. I haven't tried it yet, but it may be a reasonable compromise, particularly for single weight gelatin paper like Azo. A starch mounted print can be easily released from its support, just by soaking in distilled water. The result is flat just like a drymounted print, and seems quite long lasting. There are lots of 19th-century albumen prints out there that were mounted with starch paste, with much less regard for archival considerations than we have today, and they seem to be holding up fine. The process is described in Reilly's albumen book, which can be found at albumen.stanford.edu.