whipped this up last night, to my knowledge, there are no rules around macro usage, so this should be fair game

AHKv2 script for automating chem creation - fill the chem fridge post haste

https://pastebin.com/6BepXBhC

usage:
install auto hotkey v2
make a file, chemmaster.ahk
paste the contents inside
run the file you created
click Toggle Guide to get a GUI
activate a chem dispenser
drag the open chem dispenser's UI window into the darkened space, lining up the green dots with the menu buttons
select a chem!

be careful, some of these can get you into trouble if you misuse them