What do you define as long term? At some point, the best answer for longevity is for a company not to exist at all, given that the purpose of most companies is extraction, or some sort.
How will you handle companies that eventually go against the required guidelines?
Could a company become permanently unlisted? And how would that affect any shareholders of the company who purchased through LTSE?
Shareholders would have their ownership protected in that scenario (as they still own common shares), same as any other company who was delisted from an exchange