Nice thinking and build David. Looks like you had a lot of fun making this. I can see this could be built without the CNC. I just got my 735 this year and the stand came with it, It lives in the garage so space isn't tight enough to warrent such a stand.
But now my brain's going. I think I'd spring load the two locking pieces so they press out, then use a lever to pull them back in, out of the way. Could be a simpler build that way. The problem for me is the weight. Did I mention it's heavy? Would be nice to figure a way to use a foot lever to lift it. Using your own weight to offset the planer with maybe a spring assist. Would likely require a gear of some sort. Maybe the lever could turn a sproketed wheel (bicycle chain), that would do the lifting? At least you could salvage a couple of roached bicycles for parts.
Another option: You could also use a loosly spaced spring, maybe four, one in each corner, to help with the lift? Simpler build. The springs would compress when the planer is lowered, expanded when up. Even if they only offset half the weight, it would still be more manageable for old farts.
The spring would have to be fairly long. I'd likely enclose it in telescoping tubes, a larger one attached to the base, a smaller one that fits inside that that's attached to the top. You have at least 3 inches below the base for caster clearance, that could be used to drop the tube down as far as possible, which would accommodate the total combined length needed to contain the expanded spring. Somewhat like the way you dropped down the sliders attached to the top.
The chip ejection on the 735 is really amazingly forceful, isn't it.