Hi, welcome to the club!
I like that extra key for the added character, but you’re right: My fingers also think that the left Shift key is too small.
One thing you can do with Ukelele is: make that key produce nothing. Just create a copy of your standard layout with the command New From Current Input Source and delete the output defined for that key.
That way, you don’t have a larger Shift key, but at least you don’t get random ̀ ̀ ̀ ̀ ̀ ̀ stuff inserted.
If you do this, you’ll discover that MacOS doesn’t let you remove the default keyboard layout: at least one non-custom layout has to be present.
Let us know how you’re faring!