That's an interesting study, however I wish they took a few more data points.
During the study Extractor was applied after a 3 minute delay. Therefore, the conclusion should be edited to read (bold added by me):
Conclusion
The Sawyer Extractor pump removed bloody fluid from our simulated snakebite wounds but removed virtually no mock venom, which suggests that suction is unlikely to be an effective treatment for reducing the total body venom burden if treatment is delayed for three minutes after a venomous snakebite.
This begs the question of what the results would be for shorter delays.
My personal protocol for snakebite in the wilderness is to apply the Extractor as soon as the scene is safe - if it will not slow me down.
If I'm bit on the foot while solo, I'm heading straight for the nearest road while calling for help while I can still walk. If I stop to take my boot off it might mean the difference between making it to help or not - I might not even be able to get the boot back on.