That’ll be fine, though be aware that the older system may slightly limit the range of third-party apps that you’ll be able to use the I1 with. You’ll be fine, for example, with Apple’s Mainstage (requires 10.12 or higher) and ROLI’s Equator (10.13 or higher), but if you find yourself wanting to stump up for Logic Pro X, that requires 10.13.6 and I’m not sure whether it’s still possible to update to the final version of 10.13. I’d be a bit cautious in the first instance about updating to a later system version than 10.13.x right away; it might be fine, but you’d want to have a backup to downgrade to if you found it too slow. I can’t immediately see where the minimum system requirements are for the Artiphon editor app, but I used it for years on a Mac mini stuck on 10.12, so no problem there.