No support. Only Gens 3, 4 and 6 (that I remember) had Secret Bases. I kind of got tired of Secret Bases after a while.
I mean, just because only certain gens had this, doesn't mean that it shouldn't be added! I know a lot of people would probably love to design their bases. I mean, I've always been one for designing things in games, so I'm sure others are too! So even though you may have gotten bored, I'm sure others would enjoy this feature if it's added
Edit: Also Morzone, I looked through that thread, and saw the underground thing, but may have missed the part about making bases. I just think they're talking about digging for items in the underground's walls. If that gets added too, maybe you can even find base furniture such as gems in the digging areas. All speculation on my end lol