Interesting build. I would drop Disruption Field, replace Wall of Fire with Fire Mine, not upgrade Energy Barrage and invest some points into the Spirit School to get the Rejuvenating Barrier passive.
The thing with Disruption Field though is that Static Cage is objectively superior. Static Cage covers a larger radius, it can be cast at range, it works on far more enemies than Disruption Field (Disruption Field was nerfed in the early days of DAI so its effectiveness is greatly reduced), it lasts longer and it does damage. You can "group" enemies with Static Cage as well instead of relying on Disruption Field.
As for Wall of Fire, unless if you are planning on utilizing the fear/panic effect from Wall of Fire, I find Fire Mine, specifically with the Flaming Array upgrade, will cover a significant radius while providing very high damage and some damage over time for the same mana cost as Wall of Fire as well as giving your Barrier generation a high boost and filling up your Spirit Blade charges faster.
The Energy Barrage upgrade has very little effect. The Elemental resistance reduction only last for a very short time (about 2 seconds or so) and the alternative upgrade effectively ruins Energy Barrage.
Rejuvenating Barrier allows the Knight Enchanter to actually cast spells without relying on Energizing Step because as long as you have Barrier, you will get a 35% bonus to mana regeneration which if you add with the 50% bonus to mana regeneration from Combat Clarity in close quarters, can potentially net you a whopping 85% bonus to mana regeneration.
Personally, here are 2 ways on how I would play as a Knight Enchanter Destruction Mage.
Build 1
Knight Enchanter - 8 (everything except Disruption Field and Resurgence)
Inferno - 6 (Fire Mine, Immolate and all passives except Chaotic Focus because its bugged)
Winter - 6 (For Blizzard with Winter Winds)
Storm - 5 (basic Energy Barrage + Lightning Cage)
Spirit - 7 (upgraded Barrier, upgraded Dispel, three passives)
1) Energy Barrage
2) Spirit Blade
3) Fade Cloak
4) Fire Mine
5) Blizzard
6) Static Cage
7) Dispel
8) Barrier
This build is only for humans since it maxes out at 32 skill points which is only reachable by human mages unless if you mod the game. The reason I decided to include Dispel and Barrier is because if you are playing on Nightmare with Trials, you will need Dispel and Barrier is just good to have for the team, especially if you are the only mage.
Build 2
Knight Enchanter - 8 (everything except Disruption Field and Resurgence)
Inferno - 6 (Fire Mine, Immolate and all passives except Chaotic Focus because its bugged)
Winter - 6 (For Blizzard with Winter Winds)
Storm - 4 (basic Energy Barrage, Chain Lightning, Conductive Current)
Spirit - 7 (upgraded Barrier, upgraded Dispel, three passives)
1) Energy Barrage
2) Spirit Blade
3) Fade Cloak
4) Fire Mine
5) Blizzard
6) Chain Lightning
7) Dispel
8) Barrier
This build is for the non-human Knight Enchanters since it costs 31 skill points instead of 32 and the only difference here is the substitution of Static Cage for Chain Lightning, which happened because of a lack of skill points (unless if you mod the game). Having said that, Chain Lightning with its upgrades, can allow a Knight Enchanter to fill up their Spirit Blade charges quickly and the damage is not too shabby. You can have Static Cage on someone else or just rely on something else like Pull of the Abyss. Alternatively, if you still want to have Static Cage for this setup, just drop the Barrier upgrade and spec into Static Cage (which is perfectly okay since Knight Enchanter will generate their own Barrier)
Cheers.