The foam trick is the technical base of many cheap keyboards. As long as you do not mind to replace the foam repeatedly it might work. The compression stress-strain characteristics of foam undergoes a notable faster degradation than common steel springs or rubber. You might be disappointed about the changing tactile feedback of the key.

I am tempted to buid a FrankenBoard from an Apple Extended Keyboard II and a more recent Apple USB keyboard (I have two of that white keyboards with narrow acrylic frame). The result should have less compatibility issues than the ADB and iMate combo. Using the wireless flavour one could even avoid any case or cable modifications. We could make a keyboard with the most excellent durability and ergonomic properties fully compatible with recent computers.

Did someone already succeed in an attempt just to transplant the USB keyboard controller to the mechanics of an old ADB Keyboard?