Hello Chris,
locus could load all smaller maps as one if you use small feature. Instead of placing all sqlite maps directly into Locus/maps directory, create one additional subdirectory, like locus/maps/myMap and place all sqlite maps here. Then these maps should work as one big map. Anyway suggestion is to keep number of these maps smaller. Locus should handle on 100% maps up to 2 GB, so there is no need to split big map into many many small maps