OK, that helps.
VHF tends to be line of sight, with some exceptions. UHF is more so. Increasing antenna height would increase coverage area, or distance to horizon...
Using a distance to horizon calculation and using an approximate current height of 30 feet would give you just under 7 miles to the visible horizon. Adding another 10 feet is going to give you just under 8 miles to the visible horizon.
If your coverage issues are in that extra mile, then it would be worth it.
Also, if you are blocked by structures, and adding the 10 feet gets you above that, it would help.
If coaxial cable losses are your concern, you likely won't notice it with your ear. While couplings have some measurable loss, and the 10 feet of cable does too, it would be hard to notice without test equipment.