I see. To me, I think those feats are well balanced, certainly not over powerful. If the expertise option were not there, I don't think they would be worth it.
I was thinking, how many skills do you equate to a full ASI?
Three skills at level 4 is worth +6 in bonuses, soon to go to +9 and eventually at level 9, +12. The impact of such bonuses is divided over their applicability. Something like AC +1 applies most sessions, often several times (each time you are attacked), so has very high applicability. My experience is that an edge skill probably comes into use about once per three sessions. Core skills come into use a lot more. Perception, Stealth, Athletics/Acrobatics (because of shove), and Investigation come up most sessions, occasionally more than once. Insight, Persuasion and Deception come up at least every other session. That gives us a rough scale. We could give AC +1 an applicability of 1. Core skills might have an applicability of 0.5, but a random skill we should discount to take into account the chance of it being an edge skill. Say we call +1 on a random skill +0.2 against +1 on AC being 1. We can observe that high values in skills are worth more than average ones, so I think we need to call an expertise +1 at least equal to say 0.3. In saying that, I also observe that Expertise for a Rogue or Bard bonuses only 2 skills up front, and 2 more much later on.
An ASI must be worth more than 2, because it can give you AC +1 plus Save +1 plus several skills and tools +1 plus Attack +1 plus DCs +1 and a few other things. Valuing it at 5 sounds plausible to me.
So if an ASI is 5 and I get half of one as a stat bump, I have 2.5 to play with. That would be +12 distributed over skills. At 9th level, Skilled does indeed give me +12 distributed over skills, but how do we count the fact that the benefits scale?! I think we can simply divide by the time the game expects us to be at the relevant levels. On average over their career a character can expect to be working with +12 if they lived to be level 20. Most games peter out before then, or characters die, so we might want to ignore everything over level 12. That gives us +10 instead of +12. Still close enough given the estimating inaccuracy.
This is estimation rather than precision, but I believe it demonstrates that Skilled isn't far below fair value if we give it a stat bump. Accordingly I think we have two options
Skilled A
Increase one ability score of your choice by 1, to a maximum of 20.
You gain proficiency in any combination of three skills or tools of your choice.
Skilled B
You gain proficiency in any combination of three skills or tools of your choice. Instead of gaining proficiency in a new skill or tool, you can choose one that you are already proficient in; if you do, then your proficiency bonus is doubled for any ability check you make that uses it.
I believe Skilled A is worth about 4.5 and Skilled B is worth about 5.5 and as well as being stronger than Skilled A, is power-creeping Feats. For me, combining power-creeping and over-shadowing into one feat is doing it wrong
