is exosphrere needed to use an emummc offline if i already set up dns.mitm and 90dns?

hello, so i recently modded my switch, made an emummc and added dns blocking using both the dns.mitm file provided in the switch homebrew guide and 90dns setter app, i heard around here that exosphere is necessary too in order to avoid bans, but asking in nintendo homebrew i was told its not needed, so now im confused, is it necessary to use an emummc safely? what are the chances of the dns blocks failing?