And what if you build the Besta on the Expedit without feet? Just glue it.... Then simply make a substructure for the Expedit so that the whole thing is higher...
In terms of height, everything would already fit, whether with feet or without between the two. If I glue it, then I am not very flexible with later conversion measures. Regardless of that... wouldn't you have to sand the spots where you want to glue?!