At this point, due tot he constant flip-flopping of positions, I think that the teams' fate will be determined by a single task that will be their do-or-die. Therefore, I will eliminate the "previous performance" factor and consider each leg as an independent event.
Based on what Mel & Mike said about getting to know Ron better, I speculate Ron & Christina were sent to ES, and if only teams 4-6 do decoys, that would mean they are eliminated next week.
Now, onto my predictions of F3. Based on screen-time, the most featured teams this season, and those more likely to be on the F3 based on this, IMO are:
Gary & Mallory, Zev & Justin and Kent & Vyxsin
Flight Time & Big Easy have been recently shown to have positive interactions with other teams so far, so they might get a high placement.
Jet & Cord are being edited a bit under-the-radar, and they have the taxi-stealing karma pending on them.
Kisha & Jen are also UTR, but this is due to the editors probably not including their fighting scenes. This could be either, not including them because they are eliminated, or they go for the win unexpectedly. Another thing to consider is that they get the "...Million Dollars" quote shown in the preview and in the episode, the same as with Nat & Kat.
Concluding, I believe the Final 3 are:
Zev & Justin, Kent & Vyxsin and Gallory/Jenkisha