So, as I said in the post you quoted from, you just…don’t flavor it as items.
Ok then why do we need a Swordmage class instead of a reflavored Artificer or Artificer subclass?
Pulling this thread a little more, just use the Artificer class as is with a Homberew Swordmage subclass:
Swordmage Subclass:
Additional Subclass Spells
1st Level: Ice Knife, Searing Smite
2nd Level: Flame Blade, Spiritual Weapon
3rd Level: Blinding Smite, Spirit Shroud
4th Level: Fire Shield, Staggering Strike
5th Level: Steel Wind Strike, Conjure Volley
Level 3:
Arcane Combat Training: You get proficiency in Arcana and proficiency in Longsword, Shortsword, Scimitar and Greatsword.
Thrown Sword: A Longsword, Short Sword, Scimitar or Greatsword has the thrown property and a range of 20/60 feet when you wield it. When you throw a sword you are limited to one attack that turn regardless of the number of attacks you can normally make.
Fighting Style: Select from the fighter options
Level 5:
Sword Magic: Attacks you make with a Dagger, Longsword, Shortsword, Scimitar and Greatsword are considered magical.
Sword Step: You gain the misty step spell. You can cast this spell a number of times equal to your proficiency bonus per long rest without using a spell slot. You can also cast it using any spell slots you have. Additionally, when you cast this spell, you have the option of casting it without a verbal component but with a somatic and material component by throwing a dagger, sword or scimitar to the area you want to teleport to.
Level 9:
Sword Strike: As an action you can throw a dagger, sword or scimitar up to 120 feet and make a melee spell attack with it. On a hit the target takes weapon damage plus your intelligence modifier. You can do this a number of times equal to your proficiency bonus per long rest.
Warmagic: Same as the Eldritch Knight ability
Level 15:
Bursting Sword: When you use your sword strike ability you can choose to cause the sword to explode in a firey blast. You do an additional 2d6 of fire damage to the target and everyone within 20 feet of the target with a dex save for half damage. This destroys the weapon if it is not magical and sets fire to flammable objects that are not worn or carried.
Does this scratch the itch?