What is the correct Air Flow change per hour for my house?
Building Air Standard (BAS) is sometimes referred to as BAS - ACH This appears to be a (I begin to think deliberately, after quite a few vague web results) slippery number to track down, but it appears to be essentially an estimation of "natural air changes per hour" based on the blower door test. Simply calling it "Estimated ACH" would apparently be too straightforward for whomever came up with "BAS"...

0.35 or below is "tight" (requires mechanical ventilation below that to maintain indoor air quality.) It might be a good target to shoot towards or near, though that may be difficult on an older home. Some newer builds are evidently shooting for 0.06 and then mechanically ventilating, but that's a new build where you can take steps at the design and build phase to make things tight. Retrofitting is more difficult.

As such, 1.2 is better than 1.4, but not all that great, or all that much improvement. i.e. you still have significant air leakage.