New large blackbutt tabletop help!

Hi there..
#
I am making another table, from blackbutt, in a very similar style to this table which I completed over the weekend.

https://www.woodworkforums.com/member...-img-0936.jpeg
#
The table pictured is approx 1500mm x 900mm. the new table top will be 1500 x 1500 which creates new challenges I think in regards to the structural integrity of the top. In regards to frame and legs, I plan on using a similar 1950’s frame as in the picture above, except the frame will be cut so the legs can be attached separately and somewhat more centred and squared.
#
My question is: given the table top potentially wont be sitting on a frame, how could I ensure that it is properly structured so that the end pieces/planks don’t succumb to coming apart. I generally use titebond when laminating timber.
#
One idea I had was running some angle steel across the underside (obviously!) of the tabletop with one side of the steel imbedded into the timber where I could bore out a 3mm wide line using a router.
#
I had some other ideas but I thought I should put this out there and see what happens!
#
Any help is greatly appreciated!
#
Cheers, tom.