Is it logical to go for welding in lap joining configuration of thick plates (say 10mm). Since sufficient quantity of vertical edge is available (converse to thin plates/sheets) for butt welding. And where is the particular application.
Yes, can be done successfully, but you have not given any details on work to be done and on what material, and also, it is very important to know the material and its history before carrying out any type of welding including lap welding on 10mm thick plates.
A typical application of fillet welds in thicker steel plates is in the bottom of large steel storage tanks. Plates are flored out with an overlap, because it is much more safe (and cheaper) to make a fillet weld between the plates "as is" than to bevel the edges.