iserith
Magic Wordsmith
A subsequent suggestion elsewhere seems to be a bit better: Rather than making this a blanket rule, instead create a separate bonus for each skill that you get when you are proficient with the skill. Use it as a bonus would be the ability for some of the skills, but not all. For example, knowledge skills and charisma skills would have other benefits. This could also help rebalance some of the skills to make them more attractive.
I asked a question upthread I'd still like answered if you would: Is this set of house rules chiefly about dealing with an objection to the action cost of certain tasks in combat? It seems that way, but then there's also this assertion that it "makes proficiency more important." I'm guessing that's relative to the current importance of proficiency in that you get a proficiency bonus to ability checks? Because proficiencies are already pretty important because any bonus with the relatively flattened math of D&D 5e is a boon.