The options are wide ranging if making your own board supports.
Certainly one benefit of those steel trestles is the inbuilt facility to set up at a range of viewing heights.
The standard height settings are, from lowest height, +50, +100, +200, +300, +400, +500mm.
For example, my trestle / board interface at 2nd ht setting gives a rail height of 1m - so it can be set to 0.95, 1.0, 1.05, 1.15, 1.25, 1.35, 1.45m.
For Mr. Average, an ideal rail height for low level viewing when standing would be 1.35m (if low level is the ideal height for viewing the layout).