Hardening off station

I enjoy starting seeds inside. I dred hardening them off.  Last year I watched a bunch of videos and saw one that talked about outside in overcast weather for 3 days would do the job. I tried it, and on day 2 the sun burned away the clouds and did a lot of damage to my beautiful plants while I was at work. They also say sun in the morning and a shady spot in the afternoon, moving the plants a little farther from the shade.  This spot is not always easy to find, and I have been wrong before.
You might be thinking just do it the traditional way. I work 5 days a week 8:30 - 5 so unless I take time off work this is impossible.
What if I build a frame, like an upsidedown table. The bottom keeps plants off the ground.  The legs will hold layers of shade cloth.   1) just over the top. 2) 2" or 3" over the sides. 3) 8"/10".  4) all the way to the bottom.  The seedlings go in and stay 24/7 if it's warm enough at night when I start, or in at night if it's going to be to cold.  After a couple of days remove #4, two more days remove #3, 2 more days remove #2, two more days remove #1.  Hardening off process complete.
In my mind it seems like a viable plan. I have scoured the internet looking for someone who has tried something like this and found nothing.  Because it's rediculace and won't work?  I don't know.  
I'm going to give it a try.  I will use pallet wood for the frame. The shade cloth will depend on cost. Ideally I would love to use real shade cloth that tells me how much sun protection it gives. This may be cost prohibitive.  Worst case scenario would be using material I have, or can get cheep at the thrift shop. I like the thought of this because of cost, and I like to up cycle keeping stuff out of the land fill, but I don't know how much sun protection different material gives, so it's risky. The point is to harden off my beautiful seedlings without damaging them.
What do you think?  Am I out of my mind?  Have a suggestion to make it better?  Can't wait to hear what you all think 🤔. Thanks

Maybe a fine mesh for #1 going to the ground to give a very small amount of sun protection, and pest protection.  Then maybe a row cover, then maybe shade cloth for 3 and 4. ???

I don't know about your plan (and I don't know if this will help), but I have found out a couple things that helped me garden off plants. First they do better if you have a larger pot. I was using egg cartons and then moved up to the 8oz mushroom containers with 4-6 seedlings. Also, I put them on the east side of the house for morning sun. I did have to pull them in the first couple days but after that they did pretty well and eventually moved to the garden area (still in their pots) near where I wanted them for a couple days and then planted them. Currently, since it is not too hot yet, I do the same thing but this time the pots live outside and in the protection of the west side of the house until they are big enough to take sun all day, and then finish the same as I already mentioned.

Thanks H.
Everything is in 3 1/2" X3 1/2" pots or the large Solo type cups. I plan to put the dahlia in a larger pot today because it is definitely root bound.
Unfortunately I have dogs, the best place to start the hardening off process is in the dog area. We have 3  1 years old Sheppard mix, and they would eat, stomp and or play with anything in the yard.
I do appreciate your help though thanks.

I have done full shade (or nearly full shade) until the weekend, when I give them small doses of part sun.  Then, back into mostly shade, as best as I can manage it, until the next weekend.  It's slow, but pretty safe.  You have to commit to watching them on the weekend.

I leave mine in full shade for a few days. A couple hours of morning sun for a few days, then hope they are acclimated.

I put mine on sawhorses (rabbit/chicken prevention) and in the shade of a cherry or apple tree.  At that time of year and in my part of the world, they aren't leafed out so they give good 50% shade.  First day or two they're right under the tree.  Then I move them further out toward the drip line so they get a few hours of direct sun late/early in the day.  Then I put them in fuller sun for a few days.  I try to plant them out when a day of overcast weather is forecast.

That being said, if you don't have the right kind of shade, I think your plan will work just splendidly.  Since the sun isn't ever directly overhead, it will be sneaking under #1, 2 and 3 and toasting the plants on the south side of the table and probably west side as well.  So if the legs were overhung to the south and west (less important for the softer morning sun from the east) they'd still cast light shade on all the seedlings.  This all depends on how much taller the legs are than the seedlings.

I might propose an upside down table with legs that are just taller than the seedlings and not extended to the S or W with:

1: window screen or pest protection that goes all the way down to the table top (blocks sun from the side)
2. layer of shade cloth over that (all the way to the table top) clipped on with clothespins
3. layer of shade cloth over that (all the way to the table top) clipped on with clothespins

Then just take a layer off every two or three days.  The screen is likely only 10% shade so when you remove it, plant them on the same day - ideally overcast.  That's so they aren't unprotected from nibblers.

For once the weather cooperated, and I didn't have to do much. I've been putting my seedlings out for a a few hours a day for the last couple of weekends. This week it's been overcast and cloudy with the sun coming out for a few hours each day. All my seedlings look great.  I still have very small seedlings not ready to be outside, so I may still build something. I'm willing to bet we jump from what is almost winter weather for us to hot and miserable with no lovely spring in-between.  I hope I'm wrong. Time will tell.
Thank you everyone for your input, it was appreciated
Happy gardening