I would expect a Tow Mode switch also.
It would be similar to the second hand on a clock being at 25 minutes after the hour or 50 minutes after the hour. Now....if that's a problem.......I feel like you would notice only a marginal difference between 2.94 and 3.36 or even 3.13 with this technique. The ratios might be too close to tell ant measurable difference. For accurate calculations, count ring and pinion teeth, for rough guestimations, use the count driveshaft and axle shaft revolutions.
You'll have to turn the drive shaft and watch the tire said:If both rear wheels are off the ground...you are correct. I indicated in my first post that only the drive wheel should be lifted clear for rotation....this spins the shaft.....here's a vid to prove the point.