I wish I could answer your question, but the honest truth is that I do not know. I do woodworking mostly outdoors, so it would be hard to tell for sure. I believe that dust extraction works very well when I connect the Ridgid random orbital sander to the shop vac when using the Diablo discs. Dust escape is much worse with the small filter bag that came with the sander. Despite the apparent effectiveness of dust collection with the shop vac, I still wear a mask, but I always wear it when I am using any woodworking machine, doing hand sanding, or cleaning up.
The Ridgid sander has an eight hole pattern. The Diablo discs have four large holes that match up with the holes on the sander, so four holes are open and four are covered. There are other smaller holes on the Diablo disks which are also covered because they do not match up with my sander. The smaller holes are for five hole sanders like yours, and perhaps others.
I used the sander yesterday with the shop vac, and very little dust seemed to escape. There was essentially no dust on the board I was sanding. There was a very tiny amount of dust on the outside of the sander near three small rectangular motor vent holes, which I noticed when I put away the sander, but the sander was clean overall.
The shop vac creates suction at the work surface that make it harder to control the sander. Not that much harder. The vacuum hose ridges can also catch on board edges, the workbench, etc.
Hopefully others can offer better answers for your question about dust escape with indoor use.