Hi!
From a DM's perspective:
A player wants to play a Hexblade 1 / Swords Bard 19.
But he doesn't like using a shield on this character.
First, he imagines the character fighting more like Witcher Geralt of Rivia with all the fast, acrobatic 1.5 handed swordsplay.
Second, using a shield makes the character complicated in terms of hand usage and spell focuses.
Would you as a DM allow the player to swap shield proficiency for Agonizing Blast on level one?
Note: We're not talking about whether such homebrewed swaps should be used at all, just about this specific change.
Agonizing Blast would need a second level of Warlock or a feat usually, so it is something powerful to add.
On the other hand, losing shield proficiency is no small thing in terms of power level.
Also, the character would still be in melee a lot, Eldritch Blast would still remain a backup "weapon".
The change is meant for flavor, not for powercreep.
Thoughts? Would you allow it?
I would, especially because I believe this change would actually weaken the character.