asus 1900 gt-ac2900 rt-ac86u

Hello. I am new to this Forum. My question is how do i save changes to the Putty SSH? I have CL Fiber that uses PPPoE, and i figured out how to edit the TCPMSS. I need to make changes everytime when i have to restart router. (I am currently using Asus AX86U) Please can you help me out? Thank you

Hi I'm planning to buy that router for a node Ai Mesh or for an access point I know some reviewers said the range was bad versus the RT-AC86u, does the new firmware have corrected this ? Why this router?i know it don't support merlin but i could have a deal on it and it has 160 mhz Thanks