Just FYI not sure how familiar with warlock functionality some are, but this is going to heavily bork/neuter the class damage output. Warlock spell scaling should be theoretically double (not +1) to be equivalent - as a full output caster class. However that will still also not work as their spells scale each level with shape, not damage. Excluding weapons: L1: blast (single target), L2: chain (multi target), L4: burst (room/all targets). All are d6 default, to d8 with utterdark. The class is not designed at all to scale these spells with hitdice, as their "damage output" comes from hitting more targets (usually +1/5 caster levels). Giving them the standard scaling the other classes now use should effectively turn their pure caster variant into a wet noodle Shouldn't do as much to hybrid/melee variant - as they're more likely to rely on AOE & buffs - though it will still put them quite a notch below other hybrid caster options, as their AOEs would only slot in nicely with damage around the x2 mark as well, rather than +1 (then you have L4 and L8 equivalent).
An easy fix to utterdark would just be to make it give +1 or +2 to the hitdice of the base spell, simple fix. The others are maybe not as easy... would probably need different formula if you want them to scale nicely like other classes seem to now. Or redo their damage spell list - either might work if you like!