Also, and more importantly, how much do you alter this based upon salary?

For instance, I have read recommendations from different retirement websites that we have 3 times salary saved at 45.

It seems to me that the more you make, the less this multiplier needs to be. 3 times salary for $50K a year is much different than 3 times salary for $200K a year. If you save 20% per year and have $600K in the account at age 45, you are gonna end up with like $4MM at retirement vs $1.5MM. The $4MM retiree can practically live off the interest.