Both twins on Young Sheldon have unusual spellings for their names: Iain Armitage instead of Ian, and Raegan Revord instead of Reagan. Who else?

Diahann Carroll comes to mind.

Khrystyne Haje. From an online source:

"Khrystyne is a variant form of Khristina (Russian): version of Kristina."

Also:

"Khrystyna as a name for girls has its roots in Latin and Russian, and the meaning of the name Khrystyna is "follower of Christ". Khrystyna is an alternate form of Christina (Latin)."

Iain Armitage instead of Ian

That's not unusual; you have singer Iain Matthews with the hits "Woodstock" (with Matthews Southern Comfort) and "Shake It" (solo) in the 1970s.