You are correct in your observations.

However, if the engine is installed only slightly different from a true inverted position there is no problem. The problem, such as it is, is that many do not want to install their engines in an offset manner. They prefer there be no holes in a cowl of a non scale plane, and if there are any holes, they be located in the usual places. That insistence makes it impossible for them to do an engine just slighlty different from what they maight usually do. Gas engines, being larger than a power comparable glow engine, require more space, and gas exhaust systems are not as compact as most glow exhaust systems. That is where the "problems" arise. People do not want the stacks from their exhausts poking out in a different place and they are at best reluctant to go to an exhaust manufacturer to design their own exhaust. They prefer to leave all that stuff up to dealers and manufacturers. Then you have the potential throttle servo location "issues" where the modeler would have to make their own servo mounts instead of using the typical flat floors and pre-cut openings provided in the aircraft kit.

So much of the DLE 30 "problem" is not a problem at all when viewed from another perspective. It does not require any new parts or redesign, nor does it require internal modifications to the engine.