Comments on the Modify Spell spell.
"You can change the spells, color, sound, and smell". Any mage can do this anyways, as per the spell thematics section in Tashas. One can make the Magic Missile effect appear as if chickens, or however one visualizes the flavor the spell.
Components. "Verbal, Somatic, or Material". This is worthless, and the spell descriptions should not refer to these in the first place.
Concentration. The concentration on this spell cannot be ended by damage. This is situationally useful depending on the particular spell and depending on whether the Wizard expects to be in melee combat, rather than kiting away from the threat. Typically, this Concentration feature is not worth the casting of the slot 4 Modify Spell. But again certain situations might benefit on occasion.
Damage Type. Swap the damage type of a spell. This is awesome ... flavor. If the Wizard focuses on elemental themes and tropes, then Cold, Fire, Lightning or Thunder is superheroish. Also possible are Acid, Necrotic, or Poison, which to me feel like the primordial Elemental Chaos or else necromantic flavor. There is utility because the swapping the damage type can bypass resistance. It doesnt actually improve the amount of damage, thus doesnt cause any gaming balance issues. But it can mean your high damage spell can hit more reliably. The best use for Damage Type is planning an assault mission against a known big bad ahead of time.
Range. Increase the range of a spell adding 30xlevel. This choice of modification is a big deal. If your character likes to "kite", namely attacking a target while sniping from a safe distance away, then this spell makes that tactic easy to do with whatever damage spell seems most effective. In my experience, having good defenses and mobility, plus a few interrupts like the Shield spell, while kiting, makes the Wizard almost unhittable. Meanwhile the chosen extra-ranged spell can be a lethal one.
Ritual is poor. These spells that require a spell slot, but take 10 minutes to cast, probably need to be fixed or rethought in the first place. In any case, this modification is little or no benefit. To make it a ritual means one doesnt need to spend a spell slot ... but to cast this modification requires spending a spell slot! Maybe one or two specific spells might benefit from "spamming" as a ritual, but at 10 minute per casting, this isnt all that spammy.
Targets. Make an area-of-effect spell 100% accurate. Typically, one uses this modification to launch Fireball into a battlefield and not a single "ally" will be injured by it. Only targets that you want to hit will be affected. This doesnt increase the amount of damage, so it stays balanced in that sense. However it makes the most damaging spell more useful in more situations. This modification is worth casting the slot 4 Modify Spell.
Components and Ritual are mostly worthless.
Concentration might be useful in niche cases for a frontline Wizard.
Damage Type is meh, but I love this kind of thematic flavor.
Range is useful, but only if the Wizard is already investing other resources in the "kiting" tactic.
The Targets modificaiton is probably worth casting a slot 4 Modify Spell.