There's quite a few mods on Nexus which modify Vlindrel Hall, but I've found them all to either vastly upgrade the place into something of a palace, or they add a bunch of new non-interactable statics (a desk with a non-interactable book on it, or some armour in a chest which you can't actually pick up, for example). My only problem with Vlindrel Hall is that I want to be able to do some Smithing... So I made a mod for just that.

This mod replaces the fireplace in the main area of Vlindrel Hall with a blacksmithing forge, as well as increasing the area of that lower area and putting all the other smithing-related gear in it. See the screenshots for how it looks. This is my first mod where I've actually positioned things in the world, so there might be some bad seams or clipping in places; that being said, I did try to look around and it all seemed to be fine.

The forge and other gear is available from the start without purchasing any upgrades. If I feel like it I may one day investigate whether an additional dialogue
option can be added to Raerek to allow purchase of Blacksmithing gear, but I'm assuming it's difficult since other mods (such as the popular Breezehome FullyUpgradable) don't do it. (Having the gear disabled to begin with based off of a parent object seems simple enough, but I feel like you probably can't just duplicate an existing part of the house upgrade purchase quest and modify it a bit to enable the Vlindrel Hall smithing gear instead of Enchanting gear, for example. I'm thinking it's probably one of those things where if one mod modifies it, it overrides all other mods, so you need to write a script or an extra quest to do it, somehow - similar to adding items to Merchants being unnecessarily complicated. I haven't actually bothered to look into it all that much since it seems like it'd be difficult and I doubt anyone would care; I don't much)

I've also deleted everything that used to be in Vlindrel Hall in the area where the forge and such goes. I've also moved the floor and stairs to accommodate the extra gear, which also meant moving the main dining table. Since there were some clutter objects in that area (as well as static tables and chairs which I've gotten rid of), if you already own Vlindrel Hall, you'll get a pile of plates and cutlery and such on the floor (probably clipping inside of some of the smithing stuff as well). This won't happen if you've never entered the cell recently (e.g. on a new save or if you haven't bought Vlindrel Hall yet, you'll be fine), and the clutter should reset to its proper position when the cell resets or whatever. It'll fix itself eventually.

The smelter is scaled down to 75% of proper smelter size, mainly because the charcoal pile is a huge distance away from the actual smelter which means it's clipping through the tanning rack on the opposite side of the area at full size. This means that the animation doesn't line up perfectly, since it's playing the animation for a proper smelter. It doesn't have any effect on gameplay, though.