ALWAYS go with the original material, the surround can be considered like the suspension of a cartridge's cantilever, CONTROLLING Movement.
My vintage electrovoice 15" woofers from 1958 MUST be cloth.
Last much longer: To alter the response, more than likely detrimentally for every day of their longer life is a 'wrong' decision. Paper lasts a long time, the original surround for that size cone is likely to be around for generations!
Avoid any hvac heat discharge nearby, shut that vent to prevent premature aging/drying of the paper. Very dry house, get a whole house humidifier or if radiators nearby, add water gizmos,
https://www.amazon.com/air-vent-blocker/s?k=air+vent+blocker
