I think the reason we don't see a lot of knowledge skill is multi-fold. First the value of Knowledge skill isn't very high. Given the vast diversity of knowledge skill, getting use out of them can be very hit or miss. Even broad categorized knowledge skill very rarely get rolled.
My experience Small Unit tactics, various flavors of gang land, various flavors of knowledge local, cooperate security procedures, are the knowledge most likely to come up.
Next Logic, is not stunningly popular stat, in editions past, you had deckers run logic, and you had hermetic run logic. However Hermetics have fallen out favor, you mostly see chaos or other Intuition based traditions and of course various flavors of Cha based traditions. So that means one large constants of logic based character really is no longer seeing a lot of play.
So if we want push knowledge skill i think a couple steps would be useful. One more effective uses for knowledge, by that I mean complementary skill tests for useful knowledge. Pick a couple, small unit tactics, anatomy, knowledge Military battle, things like this give complementary skill rolls on various things in battle. Doesn't need to be shooting necessarily but things that we don't see often like leadership checks. Finding way to increase the value of various little used combat options.
Use of Hobbies, so rolling a hobby skill to "de-stress" after a fight to help recover some stun.
Things like this. Could help encourage players to see value in skills.
In terms of getting more skill on sheets I personally favor just increasing the multiplier, given that logic is currently kinda under performing compared to others, means increasing the multiplier increase the value of the stat, which seems wise to me.