It's a crap shoot.
Currently, Experian and Equifax are reporting my HELOC as a revolving line and it is counted in my utililzation.
TransUnion is reporting the same HELOC as a traditional second mortgage.
I'm on my third HELOC, and each of the CRAs has reported each way.
05/02/23 Fico 8: EX 761, EQ 775, TU 779.
Fico 9: EX 763 03/24/23, EQ 770 03/03/23, TU No idea.
Zero percent financing is where the devil lives...