Smithing Perks Overhaul is a fantastic mod. However, in order for it to work properly, you need Weapons and Armor Fixes.
Weapons and Armor Fixes is a great mod, it really is, but I disagree with many of its changes.

This mod allows SPO's new perk trees to work properly without WAF.

(Note: The improved vanilla trees don't work properly without Complete Crafting Overhaul Remade. So if you wanna use those you gotta get CCOR.)

This mod changes two perks added by the DLC. All it does is remove the tempering part of the perks.

One of these perks is massively fixed by the Unofficial Dawnguard Patch and is fixed in such a way that it doesn't seem appropriate to include those changes in a mod like this.
Therefore, the Dawnguard and Legendary versions require the UDGP which itself requires the Unofficial Skyrim Patch.
I assume that most everyone uses these mods so that shouldn't be too much of a problem.

The Dragonborn version only requires Dragonborn and there are no problems with using SPO without WAF with no DLC.

Added USLEEP Compatibility!