I do not generate fictional spaces between landuses! I generate real landuses, but I don't fill spaces between two areas by arbitrarily enlarging one or the other area just to avoid gaps to the neighbouring area. landuse specifically assigns a real area to a use! Vines should only grow where this is the case in reality. Nobody (almost) comes up with the idea of connecting vineyards to the left and right of a motorway, or forests across the motorway, just to avoid the existing space between motorways. 
I also don't orientate forest areas to summer treetops, nor do I use thousands of nodes or an endless number of multipolygons just to be able to use a single way in several relations, even if the orientation of the way is then no longer correct in one relation. And anyway: These sub-multipolygons are largely not closed and can no longer be maintained at all. The question of the extent to which further multipolygons may be contained within a multipolygon, which on their part are arranged in a featureless closed way, inner member in the outer multipolygon, is still open. 
These large-area constructs need to be completely reorganised. 