Ed..nice veneer and nice work.
I do some woodworking and have used shellac for some time. I think nearly any (desirable) finish is going to darken the veneer somewhat. I've seen kitchen cab makers use conversion varnishes that keep the wood very light, but the finish itself, appearance-wise, looked bad to me..cloudy. Though I don't doubt their finish was resistant to anything found in a kitchen. I saw their finish completely kill some (what would have been) gorgeous quarter-sawn white oak. Sad to see..I had to walk away.
I use shellac on nearly every piece I make. On a burl it would be a must-do for me as shellac pops/adds depth to the grain, curl, chatoyance like few other finishes can. Some oils do it well, but oils tend to go darker than shellac..in my experience. One other nice option with shellac, in addition to popping the grain, is that shellac can be purchased in many different natural shades..see:https://www.shellac.net/
Garnet shellac has a nice reddish-amber tint to it. There are many.
Shellac can also be tinted with Transtint. Transtint dye is great stuff. Very forgiving when you apply it as it evens out very well. It can be applied with a distilled water carrier or water-alcohol mix, or alcohol carrier. Transtint seems pricey, but a drop goes a long ways when dying wood. One thing to think about with any stain/dye application and veneer is how the dye carrier may interact with the veneer glue. Dyes look MUCH MUCH better than traditional oil or water based stains. Transtint looks terrible on wood after it dries(like mud)..but the subsequent shellac or topcoats make it look gorgeous.
For some info on how to use Transtint, see the link below. You probably won't be doing a 'mission finish', but it's a good article of general finishing pathways. http://homesteadfinishingproducts.com/stickley.pdf
Shellac is also a universal sealer. Many sanding sealers are a light shellac cut (half-pound?). Shellac will prevent subsequent finish coats from diving into the wood. Shellac can be coated with nearly any topcoat..oil or water based. Shellac itself is a poor topcoat from a water/oil resistance point of view..it's sensitive (appearance-wise) to most anything, so it isn't great in areas where finish-resistance properties are needed. Shellac can be applied to nearly any (water/oil based) finish without issues...assuming the alcohol carrier doesn't impact the base finish..and it may. Shellac is an effective conversion coat between oil and water finishes..say..linseed or gunstock oil on bare wood and a water-based topcoat. (wood -> oil -> shellac -> waterbased topcoat finish schedule)
Spraying shellac with a gravity gun makes life very easy & you get great results. Shellac can be sprayed at low temps..I've sprayed it outside at 35 degrees without issues. Just make sure the humidity isn't real high as you can get some blushing (white haze) in the finish. Shellac dries so fast it's very difficult to brush on a flat-wide surface without getting unsightly overlap..I've never been successful on flat surfaces and brushing. Spraying..easy..with great results. Harbor Freight as good-inexpensive spray guns if you have a compressor..with dry-oil free air.
If you don't like what a shellac coat looks like, wipe it off with alcohol (ethanol) and start over.
A typical finish schedule for me is wood -> transtint -> shellac -> oil or waterbased topcoat, depending on enduse requirements/desirability.
Take any furniture polishes ("Pledge..etc") and toss them in the garbage..they are silicon oil based..aaacck!
..quasi random thoughts..