blizzard does know you are using multiple accounts, their warden system is checking that stuff, they allow up to 8 accounts per person in their TOS, as long as you do not use something that "automates" the process, that is left vague on purpose.
safest way would beb several virtual machines in one pc, that ones is fully legal but you need a beefy pc. most common way is to just use windows process explorer to deactivate the "check how many instances are open" part of the d2r.exe. Legally they can ban you for that, but they dont, they are more likely to ban you for doing trav runs 300 times.
with regards to graphic mods, they can absolutely ban you for that.
This post was edited by Ashina on Feb 15 2023 09:57am