I feel like I should add in my two cents about this, since more information about why it should be tweaked would be good in order for a more compelling argument. Originally Alchemy allowed you to create a potion, such as Speed, and then you could simply 'switch' between redstone and glowstone for shifting between stronger potion or longer lasting potion.
You would get xp for each of these' switches', which would make it easier for someone who was leveling potions to work with. You'd still be creating a 'new' potion, using up ingredients, as well as using up time and getting xp while doing so.
However it seems that MCMMO has since 'fixed' this since it was 'unintentional' as I've heard. However this makes XP gain in alchemy a lot harder, as now you will have to drink every single potion that you create or simply toss it away. This requires you to: Spend time 'drinking' the potion or 'making' new potion bottles, filling said bottles, and putting them back into the brewing stand.
All of that takes up extra time in which you are gaining no xp.
Now I did a little testing just now about the xp that you are gaining from alchemy, I am currently at level 550 and it requires me to have 16,770 xp to gain a single level.
3 water bottles to awkward potions: 74 xp from this
3 Awkward potions to speed potions: 149 xp from this
3 speed potions to longer time potions: 297 xp from this
So going from a water bottle to a longer time/stronger potion gets you: 520 xp.
And all of this testing was during a x3 xp event. This means that all of the xp I just gained would normally be 1/3 of what I got. So 'regular' xp gain would be:
3 water bottles to awkward potions: 24.66 xp from this
3 Awkward potions to speed potions: 49.66 xp from this
3 speed potions to longer time potions: 99 xp from this
So going from a water bottle to a longer time/stronger potion gets you: 173.32 xp.
So in order for me to level one single time I'd need to fully brew:
96.75 potions during an x3 xp [or 32.25 brewing stands].
290.272 potions normally [or 96.757 brewing stands].
Now please note that the actual work you have to do is three times as much as what's here. Because you have to do those potions/brewing stands three times in order to get the full xp. Once for the netherwart, once for creating the potion, and once for the redstone/glowstone.
Now taking this into account, the amount of times you need to create something in order to get the single level is:
290.25 potions during an x3 xp [or 96.75 brewing stands]
870.816 potions normally [or 290.271 brewing stands]
Potions take a super long time to brew, especially because MCMMO alchemy skill makes it take even longer at lower levels.
So the amount of xp that you get right now is incredibly low for the work that one is doing.
I'll also point out that you gain absolutely no xp for making a potion that's MCMMO-exclusive now. So that's kind of a bummer as well because you're not even gaining xp for brewing specific potions. Which is the entire point of the skill.... to gain xp from brewing.