Seen it done by others and done it myself for a dozen or so customers once waranttee has expired.
A couple of tool holder cleats in the left fender to hold the wand out of the way hardest bit is finding a spot for the on off switch so the operator does not have to take their hand off the control arm.
A little tricker with some lap bars than others as you need one hand for the spray wand and the other for both of the lap bars.
When you make the rack, it has to be high enough to get the engine cover off and tools ( rattle gun ) on to the flywheel nut.
OTOH when you have several miles of fence line to mow & spray, makes a very big time saving.
Have done similar to tractors with a 5 gal drum sitting on the tow hitch.
You also need to find or make a very long wand.
