Has anyone done any testing on using a magnet with a steel plate, versus pairs of magnets?

I did some research on the K&J site. What they say is the pull force required to separate a magnet from a steel plate versus a magnet from another magnet is exactly the same if the two are in direct contact. If there's a gap, though, say from coatings and veneer, then the pair of magnets will be significantly stronger than one magnet with a plate. However, assuming a 1/10" gap, one 3/16" thick DC3 magnet with a plate is stronger than a pair of 1/8" DC2 magnets. Potential advantage of a plate is it could be thinner and wider than the magnet - e.g., Amazing Magnets sells a 1" dia. by 1/32" thick zinc-plated steel disk for 10 cents, so maybe no need to thicken cover edge and easier to align.

Anyone tried this? If not I'll see if I can do some testing and will report back results.

here's the data:
DC2 (3/4" dia., 1/8" thick) is 9.76 lb pull force at full contact. Paired magnets with 1/10" gap will have 3.1 lbs * 8 pairs = 24.8 lbs total

DC3 (3/16" thick) is 15.5lb at 0", with plate and 1/10" gap is 3.92 lbs * 8 = 31.36 lbs total
DC3-N52 (3/16") is 19.2 lb at 0", with plate and 1/10" gap is 4.85 lbs, so just using 6 gives 29.1 lbs total
DC4-N52 (1/4") is 23.3 lb at 0", with plate and 1/10" gap is 6.11 lbs, so just 4 gets you to 24.44

--s