That... sounds awfully like ammunition to me... raw material (projectile) and energy (ignited fuel source).
That's like saying the water in a coffee machine is ammunition, or the plastic feed in a 3D printer is ammunition, or printer ink is ammunition, sure you can call it that, but it's wrong. It's stock, or supplies, or raw materials, not ammunition. ED tends to use the word ammunition......almost universally for things that both are and aren't ammunition in the proper sense of the word. The AFMU is using raw materials to repair the ship, Shield Cell bank is using stored energy to restore the shields, limpet controller is a computer that tells limpets what to do, it doesn't store or fire them.
Limpets are general use, I can have multiple different types of limpet controllers on my ship and they all use the same limpets, the limpet controller just programs them. The OP wants the limpet controller to store the limpets, now that may be a reasonable argument for a small ship carrying a single limpet controller to save cargo storage space, but my miner has 4 limpet controllers, do they reload themselves from the cargo as they run out, do I need to manually reload, if it's automatic why not take them straight from cargo? Then the OP wants to synth limpets for a specific limpet controller, that means I have to do four synths to get my limpet controllers all working instead of them just grabbing what they need from the cargo.
Much better to have the limpet launcher (we must have one right? It's just never mentioned, must be standard on all ships) to store limpets as "ammunition", that way one synth reloads all my limpet controllers. While I can see where the OP is coming from, the idea is really only useful for small ship with low cargo space and one or at most two limpet controllers, he just want to not have to store limpets in general cargo space.
It sounds overly complicated and unnecessary and confused because of FDEV's use of the word ammunition to cover many things which are different things altogether.