Help - need solution - Breakdown joinery options

Ok, so I’m preparing to build a portable dance floor. Basically, it is a bunch of 4’x4’ panels of 1/2” plywood with a low-profile grid-work of hardwood slats on the bottom, laminate harwood-type flooring on the top. Each panel has to connect to it’s neighbors in a way that will not pull apart, nor raise above the adjoining panels. For example, a 400 sqft dance floor will consist of 25 panels laid out in a 5×5 grid.

The manufactured style portable dance floors will typically have some sort of aluminum channels that basically “click” together. Here is an example of a commercially available floor system: Cam-lock. I need a solution that I can easily accomplish in the home wood shop, and won’t cost an arm and a leg.

Until recently, I had never heard of “Lamello” systems, nor their “Clamex” product. This would be a perfect solution for what I need, but it is cost prohibitive.
Here is a link to an American Woodworker article on this product: Clamex
The Lamello tool itself, which operates like a biscuit jointer, is over $1400. The connectors are $200 for 80 pairs, which is tolerable, but the tool is a deal breaker.

Any ideas from the Lumberjocks Brain-trust? Thanks in advance for any help and/or advice.

-- Allan, Portland, OR