As a suggestion, S Ranks should spawn with an active invulnerability buff which lasts for a few minutes (like 5 minutes). That will not prevent sniping as much, but people might find the S Rank engaged while not being relayed. For Early Pullers it just means they can't do that anymore and people can actually make it.

In regards to old Elite Marks such as in ARR, a second buff could automatically be applied upon engaging which makes it impossible to kill for a fair amount of time (like 1 minute).

Elite Marks such as Senmurv, Thousand-cast Theda, Zona Seeker, Nunyunuwi, Leucrotta, Udumbra and Ixtab are incredibly time consuming. And seeing those being pulled instantly is very punishing towards the person who actually invested their time. The use of third party tools are making it worse in that regard,