In retrospect I should have gone with the DX8 instead of the DX7s for just this reason (also 3 position switches on most things, instead of 2). DX7s is a good Tx, but the backlight would have helped in many situations.
AS for the dx8 screen being a direct swap. I don't know. I thought the dx8 screen also had a bit better resolution too. May be remembering wrong. If it does, then likely not able to be swapped in.
And cost difference on these components, even in bulk, can be significant. Enough for $30 to cover with profit, sure, but then it screws with HH's intended price-point breakdown on the product. In order to keep their price-point and put backlight in, they might have had to remove the rubber grips on the sides (and that may not work either since they wouldn't want to have a separate mold for DX7s from DX8, which also screws with their costs and pricing) or go with a cheaper plastic (affecting overall quality and warranty costs). It's all a balancing act.
