Something I have found frustrating is blenders massive shortcoming against programs such as solidworks for simple booleans and fillets and other simple hard surface geometry. I have started to discover some decently quick and clean methods around this and here are my most recent results-
The first thing ive had an issue with is trying to fillet complex edges correctly. Even when i had simple topology the bevel tool would give awkward results
Well the problem with having so much geometry is having to clean up the mesh which would probably take more of less the same amount of time as adding the loops normally.
Would be nice if there was a tool that automatically added edge loops to make corners smoother without messing up the topology.
I mean if I leave the geometry more simple I do not get the consistent concavity/ radius on the fillets and stuff, and I’m aiming for the cad like precision on that. It is essentially generated geometry with only a bit of tweaking, so its not like it is consuming time to get the geometry at least.
I wrote a post for blender nation that touched on using minimal geometry for hard surface modelling which may or may not help. I’ve found that it’s best to have the bare minimum of geometry and use the sub-surf modifier to add the curves
From your examples above I can see how you could model it with octagons for the circles and edge loops to define how they join.