I have had good luck with simple predator calls for Sitka blacktails. A fawn distress absolutely works, especially during the early season when does are still very protective.
A couple things that have worked for me:
• Primos “Lil’ Dog” or similar closed-reed predator call – easy to run and gets a good fawn distress sound.
• Fawn bleat calls like the Primos “Still Fawn” can also work if you want something more subtle.
• Start with short 10–15 second bursts, then sit quiet for a minute or two. They often come in slow and curious.