Never seen any actual field test data comparing carbs w/ and w/o the barometers usefulness. In theory it should help some but as you mentioned it won't perform the same as a computer controlled EFI system. The mc alt comp unit is just a barometer that when atmospheric pressure drops at elevation it opens up a tiny passage that allows a tiny bit of extra air to lean the mix. Pretty rudimentary system but does help some. "Some" is a relative term as in it helps but is NOT a work around for proper jetting. If yours hasn't been buggered by some previous owner, (not owner adjustable) I personally would not want to lose the barometer. Won't run as well as you hope for at elev but it'll run worse(rich) at elev w/o it. I wouldn't spend money on another carb just to get rid of the alt comp unit. Best thing you can do is keep your motors ignition and carb system tuned to the Nth degree and learn to live with it or rejet and tune for elevation. I used to work in the mountains/Rockies/Cascades in the 70's (geology) and on V8 Chev/Ford/Dodge for short term work I'd advance the ign timing 2* per 1,000ft above 7,000 ft. It helped. If the job was going to be weeks long I'd rejet for the duration and rejet again later bakin civilization.
If you're just hwy traveling through an area and encounter a high pass 7,500+ ft and it's bogging down from running rich you can temporarily remove the air filter element till you crest the summit. No cheap easy bandaids for proper jetting and tune long term