I use to work in several different service station near a Marine base back in the early 1960s when rope seals where stock OEM in all new Mopar motors, I saw more than one rear main seal leak back then
I've rebuilt motors and had to use the OEM style rope seals, once the new style rubber and later Neopreme came out and now the newest Viton seals sold today I haven't had a rear main seal leak in over twenty years, I have had the old side seals leak on BB Mopars years ago but not anymore
If the factory can make the stock rear main seals not leak then we should be able to get the same results, no matter which type or material used
The old technology and parts where invented years ago, they are not as good as the modern ones used today