Modify Memory and My Dimir Character

So I have yet to play in a Ravnica campaign, though I'm planning a 1-shot for level 18 characters that will be set there (one of my friends has a level 18 character she never gets to play, so I volunteered to dive deep.)

Anyway: I realized something horrible. I had, for a long time, been thinking about a House Dimir Half Elf Shadow Sorcerer (infiltrating the Izzet League) but I just realized something terrible:

Sorcerers don't get Modify Memory.

OH WAIT! YES THEY DO!

I literally started writing this post feeling crestfallen before I remembered the Guild Spell Lists! Yes, given that it's one of the most House Dimir-like spells, it should not come as a shock that Dimir Operatives who can cast 5th-level spells get access to Modify Memory.

So disregard that earlier sadness!

Now:

I had an idea for a way to use Modify Memory in an unconventional way: Generally, I think most people would use it to act as something like a neuralizer from Men in Black - you erase the memory they had of seeing you do something you didn't want them to and replace it with something mundane and unremarkable.

But I realized that it might solve a problem I made for myself earlier in my campaign.

First off: I think DMs have a ton of license to break the rules if it means a better story. If you need to force your players into a situation for the story to work, that's ok as long as you make sure the players don't feel railroaded. Make sure that there are big choices for them to make. Matt Mercer has been remarkably adaptable in Critical Role's campaign 2, which is amazing, but you don't need to hold yourself to such a standard (like, spoiler alert, totally upending one of the main plots of your campaign based on what the players do.)

But still, if there's a way to do what you want to do within the rules as written, you should try to do it that way and thus give your players a chance to mess with it.

So:

In my campaign, there is a shady, clandestine organization that seeks to manipulate events behind the scenes for their own purposes (they see themselves as lawful neutral, but veer into lawful evil a bunch,) called the Khorem (they were the magocracy of a long-fallen empire that have supposedly not existed for thousands of years.) The Khorem has some strange plans involving gold dragons and the Shadowlands (my world's Shadowfell equivalent) and has thus been keeping a close eye on the paladin in the group, who is a Gold Dragonborn.

In initially introduced them by having the paladin spot two "men in black cloaks" (get it, men in black?) who seemed to be watching him at a pub, yet when he went to confront them, they were nowhere to be seen and no one else at the pub seemed to have seen them there.

Now, to be fair, I kind of threw that in as spooky flavor. I didn't really have a mechanic other than some kind of selective invisibility or something in mind.

But now I've figured it out: Modify Memory.

See, yes, it's usually there to remove remarkable memories. But you could also use it to have an entire briefing that no one who can't extract the thoughts directly from the subject's mind could overhear. Rather than approaching someone and making sure you're in a spot where you can't be heard, you instead just add a memory to their mind of having had the meeting - the memory doesn't seem to have a hard cap on how complex or long it is, so all you need is a few moments to cast the spell on them.

This could be done in a benign way, or it could be a way to threaten someone. Naturally, you could also seed paranoia by having a trusted NPC or even a fellow party member be the one giving the message - and then the subject might think that the other character has been charmed or mind-controlled.

So while the exact goals of freaking the paladin out by adding a memory of seeing these dudes in black coats remains... elusive, I think this could be a really interesting way for people like the Khorem (or House Dimir, who largely inspired the Khorem) to communicate.

EDIT:

For fun I decided to just roll my Sorcerer character for hypothetical future use. I managed to get some insane stats: at level 1 he's got 19 Charisma and 17 Constitution. No minuses (which oddly seems to be a thing with characters I roll.) So that means that at level 4 he maxes out Charisma and gets a +4 Con modifier, potentially maxing out Constitution as well at level 8. Oh, and +2 to Dex, so while he's always going to be a little squishy as a Sorcerer, it's not that bad. Plus, given that he's embedded in the Izzet League, as long as he doesn't get found out he might be able to earn himself a Mizzium Apparatus (or steal one!)