It should behave identically in 4-hi as in 2-hi when in "D"
In 2hi, 4hi, or 4lo, if you have the lever in "1" or "2" the overdrive is not an issue, as it is really nothing more than 4th gear. Putting the selector in "1" will keep you in 1st, "2" keeps you in 2nd or lower, and "D" keeps you in 3rd or lower if the OD is off. Turning OD on allows "D" to become 4th or lower.
In 4-lo the same will be the case, but obviously your speed ranges will be different. There aren't many times you'll find a need to be at a speed where the transmission will go to 3rd or 4th when in 4-lo, you really should be in 4-hi at those speeds, and even in 4-hi you probably shouldn't be going fast enough to be in 4th if you really need 4WD.

I really only use my OD off button for climbing/passing and for a little extra engine braking on the highway (I don't tow).

Using a lower gear ("1" or "2") will not provide more torque per se, but will keep the engine from shifting prematurely and allow you to make use of the torque provided more efficiently rather than gunning the engine. 4lo provides more torque than 4hi though. Experience is really the best way to get a feel for what is appropriate. Generally, if you find yourself revving the engine without getting much response, try 4lo instead, you'll be surprised.

Brent