is this risky at border control (90/180 rule question)

my boyfriend (new zealand citizen) stayed in lithuania november 20 2025 – january 15 2026 (57 days). planning to come back june 15 2026 and stay until september 9 (~86 days).

i know about the 90/180 rule, and by june 15 he would only have around 60 days left at entry, but hed be regaining days while staying.

is this risky at border control since his planned stay is longer than what he has left on arrival? do they take into account that he will regain days, or just what he has at entry?

also would it be safer to book a return for early august (within 60 days) and then change it later to september once he is already in lithuania, or is that still risky since we are trying to avoid any chance of refusal