At the moment Glass+Lights enables a recipe at the glasswork station, which for 1 glass and some clothes makes Molotov Cocktails.

However vanilla has already the molotov cocktail recipe at the machining table, which also requires chemfuel. It seems a bit of an exploit to be able to do it just with glass and cloth.
I would rather disabled the recipe added by Glass+Light and add glass to the vanilla recipe, like this:

<li Class="PatchOperationAdd">
<xpath>/Defs/ThingDef[defName="Weapon_GrenadeMolotov"]/costList</xpath>
<value>
<Glass>2</Glass>
</value>
</li>