Block temporary e-mail domains

I would like to protect my site from being spammed with loads of fake accounts by (among other used tools like google captcha) blocking temporary e-mail domains that could be used for creating fake e-mails within registration form.

UM/settings/access/other has the option of entering e-mail domains to be blocked and my question is:

I believe that we can add unlimited number of temporary e-mail domains but I don’t know are they going to slow down my site (or overload my shared hosting) if this list is too long.

I want to add domains from the lists (links) bellow:
Temporary domain list 1
Temporary domain list 2

Eventually, I would add even more temp domains if I find them.

Looking forward to your reply. Kind regards & thank you !