Indeed ISFP 5 isn't typical. At the same time it doesn't seem totally atypical like ISFP 8 (or ISFP 1, to a lesser extent). ISFP 5s seem to be prone to mistyping as ISTPs, a 1-letter difference.
Thinkist: not optimist nor pessimist. I am primarily competent in the enneagram.
SX 9w1, SP 5w6, SP 3w4 | Split with the first two
Ti-Se-Si-Ni-Te-Fi-Ne-Fe. I'm always questioning this, particularly the Si.
Big 5/Global5/SLOAN: RCUEX