Part-time CPT won't impact your H-1B eligibility since it doesn't affect your OPT eligibility.

Participating in part-time CPT won't limit your future H-1B eligibility because part-time CPT doesn't count towards the 12-month limit that affects OPT eligibility, which is often a stepping stone for H-1B.

Since part-time CPT is 20 hours or less per week, it doesn't impact your eligibility for post-completion OPT, and subsequently, shouldn't directly affect your future H-1B eligibility.