For a small iSCSI SAN, there shouldn't be any issues using a Meraki switch. The Meraki switches can absolutely handle jumbo frames (specific sizes vary depending on the model, but most are 9570+ bytes max size). The support for jumbos and specific limitations are in the specifications tab of each switch. The only current model I didn't see it mentioned on was the MS350s, but all the other MS1XX/MS2XX/MS355/MS4XXs did mention jumbos and their specific limits.
The biggest concern with using a general purpose switch for storage uses is when you start pushing large amounts of bandwidth through it. Unless the switch is capable of line-rate forwarding, you can potentially have dropped packets. For normal IP traffic this isn't a big deal, but when you drop packets in a storage environment, it's a big problem very quickly and some systems do NOT handle these drops gracefully (you're doing the equivalent of yanking the cable to your hard drive out in the middle of writing to it, which tends to lead to bad things happening).
