I disagree with this
I did this multiple times, when I need new proxies for other projects,and I changed 50+ proxies in MP.
I got some PVA or password resets, but if you don't mind PVA, you can do it.
Disclaimer: I did this on aged accounts.
And one Q for all
Please check this thread, I have some project to start but I don't feel good making 50 prelanders