Since this is the most likely scenario for our group, I would like to talk about this.
I think both options are viable.
Option 1 is the playoff format, so it would be a good idea to already play it in the tiebreakers.
Option 2 is a bit cooler, since it is less work for the teams and gives some space for tactical stuff, but it is more likely to get another 3-way-tie since there are less matches to play.
I already mentioned that both of this options can potentially lead to a tiebreak again. This is my main issue with this solution, but tbh I've thought about this for a whole day and didn't have an idea to solve this without using a lottery in this very unlikely case or go with the seeding, which would give an unfair advantage to the higher rated teams and make upsets harder.
Since it is very unlikely to happen, I would just take the risk but go with Option 1 where the risk is a bit lower.