It looks like you use two separate sets of DACs to get the low frequency and high frequency signals. Interesting.
Do you have a USB connection to down load the ARBs.
Because you have "soft controls" you can down load new functions later. (I hope) Another use for USB or blue tooth.
With very old function generators, I often spin the frequency know from one end to the other and watch the scope. many will sweep 50:1 (looking for filter response or amplifier response) The new generators act very differently.
Example: 1khz, 2,3,4,5,6,7,8,9,10,11,12,13,14.......1501, 1502, 1503 1504, 1505 See how slow the know increments on the right side.
I would be thrilled to have a "log increment" option.
Example: 1khz,2,5,10,20,50,100,200,500,1000 (or increase 10% with each click)
I know you probably have a sweep function that will solve the problem.
I have designed pieces of several function generators. One of the uses is "testing". Where a PC controls many pieces of equipment. Example the PC directs the generator to output 10hz and the AC meter measures the out put voltage of the amplifier under test. Then the frequency if set to 20khz and tested again. (factory automation testing) But your generator will need a network or USB or serial connection.