One longer bullet can be acceptable if it is genuinely the strongest accomplishment, but every extra word should earn its place. Recruiters still need to scan the page quickly.

Try to preserve the action, scope, and result while removing process detail that can be discussed later in an interview.

If the bullet requires three lines because it contains several separate achievements, it may be better split or simplified. If useful, this guide on consulting resume guide gives more detail.

3 lines is probably too much unless bullet is insane.

cut process detail first. result matters more.