It's similar to what I've been doing for a long time but with a smaller box...
About 25 years ago I was poking around in the local Ace Hardware store and stumbled upon some inexpensive small non-adjustable compartmentalized parts boxes measuring about 4-1/2" W x 8" L x 1.5" D with six compartments running width-wise.
I bought one and when I got home, I happily discovered a spool of thread, wire, floss or tinsel fit PERFECTLY lying on its side in the compartments and I could get 4 spools of whatever in each compartment for a total of 24 spools in a box.
The next day I went back to the hardware store, bought all they had in stock and had them order me some more and organized all of my spooled stuff by material & size and color.
I did the same thing with my Pearsall's thread but went with a smaller Plano Pocket 5 - Compartment box that fit the smaller Pearsall's thread spools better.
YMMV but I like the smaller size boxes because each box holds a specific size of a specific spooled material versus one large box with everything. The smaller boxes also transport better so if I am tying on the road and don't anticipate needing something, I just leave that "spool" box home. When I'm tying at home, the boxes sit on a shelf beside my trying bench.
I also like the smooth dividers without the "bumps" for the adjustable dividers.
I will confess that at least in the case of thread, the boxes really serve as "extra spool storage" because I have more bobbins than brains so all of my bobbins are loaded with the thread sizes and colors I use most often so I don't have to swap spools of thread all the time.
If I'm tying on the road, I just grab the bobbin(s) with the thread color & size I think I'll need. Wire, floss and tinsel is never dispensed from a bobbin in my world so those are the only spool boxes I'll transport IF I need wire, floss or tinsel for the flies I plan to tie on the road.
A couple of recommendations:
If anyone goes this route, grab a spool of thread and peruse the shelves in your local hardware store, the Walmart sewing & crafts section or places like Joann Fabrics for small craft boxes that you may like better. IF you find something you like, buy a LOT because they tend to disappear. That's what happened with the boxes I bought from Ace... 🙁
If you go the tackle box route, resist the urge to use adjustable dividers to further compartmentalize spools. It makes it a LOT harder to get them out of the box and they usually don't stay in place.
Look for boxes with non-adjustable dividers in the size you want. The smooth compartment dividers just work better and IF you have slightly wider spools, you may find you will be able to fit more spools between those compartment dividers if they don't have the adjustment bumps sticking out.
IF you think you want a box with adjustable dividers, look at
Meiho tackle storage boxes from Japan. They make all sorts of sizes and compartment arrangements and Meiho boxes are the ONLY adjustable tackle storage boxes I ever used where the adjustable dividers stay put.
Good luck!