This is my attempt at an alternative to Keen Mind, that's more generally useful for a "smart" character.

The problem with keen mind is that it's extremely situational; knowing which way is north is only useful if you don't have a compass or can't observe the sky, likewise with knowing the time of day. As for the perfect recall, I've never played in a campaign where players had to roll to remember things if we took notes (and even if we didn't our DMs usually just reminded us of what our characters had been told), usually it is up to us to decide if we play a character as forgetful or not.

On this basis I decided to remaster Keen Mind as an INT half-feat granting a skill proficiency plus advantage to investigation checks for solving clues and riddles (so more problem solving than observation) and to recall information your character might know (e.g- have heard a rumour, an old legend etc.). This way you still have the benefit of being able to roll with advantage if your DM does ask for a recall roll, otherwise there's wiggle room to argue for advantage when a piece of information fits your character's background somehow, e.g- recognising the name of a noble when you are yourself part of the local nobility etc., though it's still up to your DM how generous they should be with this.

I hadn't intended to include Perception and Sleight of Hand in the skill list for the proficiency, but unfortunately there is no option in D&D Beyond homebrew yet for "Choose an Intelligence skill" so this was the closest I could find; that said, perception or sleight of hand may fit certain flavours of character quite well so it doesn't bother me much.