You're insect dusting schedule seems great! Feeding three times a week is a bit scarce according to me, but toads are excellent judges of appetite. As long as you monitor body weight and activity levels, then things should be perfectly fine. You may want to keep trying to feed on other days, as well. Make sure they are still nice and chubby, and about fifteen minutes of "eat everything you can" may be given on those days. Toads appetites decrease slightly in the winter months, so maybe them not feeding everyday is a result of that.

Also, what feeding method do you use now that they aren't using tweezers?