but doesn't it have to be cut out more to make room for Sinkit clips? Am I responsible for that? How do I prepare for laser templating?

Good questions for your countertop people.

I can only speak to my own (ca 2010) kitchen reno, but I supported my large SS sink on steel angle attached to cleats on the cabinet walls. But however it is supported, the top of the sink flange needs to be no higher than flush* with the tops of the cabinet sides that are supporting the stone. And while you are at it, use a large level to ensure that all sides, fronts, and backs are level and in the same plane.

To minimize stone damage, one would cut the stone slightly larger than the sink upper edge shape so accidental bumping by pots and pans will more often intersect the sink edge and not the stone (in my case soapstone).

And discussion as advised with the countertop people is a good idea.

*a thin gap between stone and sink metal will facilitate a layer of silicone sealant.

Kaseki - Very helpful - thank you. Sounds like you're suggesting a slight positive reveal? I had not considered doing that for the purpose of protecting the edge of the granite sink rim.

My large main sink (29.5 x 16.5) has 1/4-inch positive reveal in soapstone; my significantly smaller prep sink has zero reveal (flush) fitting in granite. Generally, things in contact with the edges of the prep sink are soft. Nonetheless, it is best to expect that stuff happens.

@Joseph Corlett, LLC - might as well bring the expert in to answer OP's questions!

Here is a photo. Granite sales guys says if it were him, he'd take a Sawzall (reciprocating saw) to that right side to cut out that 1/2" strip of wood clean & flush to the cabinet wall to create some space there. I agree since I want to move the sink to the right as much as possible (which is the whole reason for using HUSH). Agreed that I should cut back that strip all the way to the sink base cabinet right side wall?

M A: Where is the photo, please?

Ok, hopefully this attempt to post a photo works.

With the exception of the front rail, cut out as much of the top plywood as you please. Especially the rear; make it easy on the faucet installer, please.

You may even relieve the top of the right cabinet side to make room for your sink flange.

Ok, I see what you're saying. Makes me feel better that my thinking was tracking. Who typically makes these additonal cut-outs? Noted regarding front rail - thank you.

"Who typically makes these additonal cut-outs?"

The person installing the sink.

For clarification, I'm going to have Sinkits clips on three sides of the sink: front, back & left. Fabricator won't work with me if I do HUSH alone.

I need to get a longer piece of wire than than the 50-inch coil of "easy-bend" wire that came with the HUSH. This is for the left side of my sink base cabinet which per the photo above extends into the recess corner of the "L". Per BB Industries web site this wire is 1018 galvinized steel. Learned galvinization prevents rust and corrosion. What guage is this wire? Where could I get more of this wire? Is this the same I reached out to BB Industries but didn't get anywhere. I want to be sure to get the correct wire so it holds the sink for many years to come.

"Where could I get more of this wire?"

Buy another HUSH and tie the wires together.

It seems to me that for templating, one would want to position the sink using some temporary mounting scheme that establishes location and height. This would of necessity require removal of excess top plywood and any cabinet side upper edge that causes the sink to be proud of the countertop base plane. Whether this jury-rigging is done by the home owner or by a carpenter is up to the home owner.

What's a good method for tying wire together?

Note I have had the subtop cut out to make room (near wall) for faucet, disposal air switch, and to have access to mount HUSH clips.