Ahh yes, the part about calculating whether it would be worth delegating HP to receive HP is really for someone who is active, voting every day, either manually or automatically, so if you are voting and your VP is always moving, it may be better to keep the HP for yourself.
Now for an inactive person, it really is worth delegating, because that way your HP will work better and have a greater chance of having a high return. Passive income is something I have been looking for too, in fact I increase my HP with the return of posts, and HBD has been multifunctional.
I buy L2 tokens with it, a little Hive Power UP, another amount in savings to yield and use as a reserve fund and I avoid powerdown at all costs, I really want to grow more and more around here.