New subwoofer on the horizon

A question addressed to everyone, including you @Chris_Brunhaver, if I do not disturb you:

in the meantime, as I find the perfect subwoofer for my AV system, and set aside the necessary sum to be able to purchase it, I have a doubt that grips me.

Would I run any risk watching movies by sending all full-range signals to my only two towers?
(I have the PL500II)

My concern is that they may not be specifically designed for the reproduction of LFE signals which, especially in the latest films, I must say, “put a lot of strain” on the woofers.