My IA who helped build Glenn's engine in my hangar preferred this "laying on it's side" approach too.
Simple to do, just cut wood supports and attach to a plywood base. One support under the mounting "ears", and one under the front bearings, size them to keep the crank horizontal. Easy to do...
He also suggested another approach for the later work... Hang the engine on the plane without the cylinders attached. Light enough that a hoist is probably not required, and easy access to the mounting bolt nuts. It's just as easy to put on cylinders with the engine horizontal on the plane as it is for a vertical engine on a stand.... I got to prove this when my Tiger needed a top overhaul...
gil A