Are we doing this again?
You have 4 options in November (lumping all 3rd party candidates together). Only 1 is likely to prevent a Trump second term. That's not an opinion, it's statistical fact.
If the sum of your utility on all issues (some kind of benefit/harm multiplied by likelihood) of Trump is greater than Biden, you should vote for Trump. If you place an infinity of harm on any one issue, and assign that to only one candidate, then you decide that way. (I.e. your red line). That's fine, but in my opinion irrational and detrimental to the world. But it's your opinion, your vote, so you be you.
What seems the incredibly likely outcome here is that enough liberals aghast at Biden's inability to reign in Israel will choose not to vote for him, Trump will sneak into power and make things worse in every area, including Gaza, at which point said non-voters will hopefully reconsider their staunch position if, there is in fact another election.
Personally I'm trying to make my peace with a second Trump term as the maga voters need to suffer, more, because clearly the actual actions and words of Trump mean nothing to them, and they're so poorly educated on important topics that the only way you can reach them is through actually seeing what a god-awful choice Trump is for them personally. Maybe another 4 years will be enough. Like lancing a boil. Which Trump is. They believe that sticking it to the system, to the elites is a good way to show their displeasure at how the country seems to have abandoned them, when in fact all it will do is remove more of the safety-nets they require to live, remove rights that are crucial to their future well-being and create an even larger gap between themselves and the elites.