There's at least 1/16" rearward movement available before any loss of contact area between the nut and the trackend, so you'll be fine for using the chain up until it's time for a replacement; even without changing to a 17t.
@BringMeMyFix started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
There's at least 1/16" rearward movement available before any loss of contact area between the nut and the trackend, so you'll be fine for using the chain up until it's time for a replacement; even without changing to a 17t.