Manufacturing was always a tougher thing to get into, I was working on it with one alt when I played many years ago, then tried using other characters to pick up some salvage or items from level 4 missions etc that can be used (using the old alt in a Noctis to beam in and salvage then loot everything haha).

It is handy when you can make enough in game isk to cover Plex cost for the month, mine was using a nicely fitting Golem with a few faction items and of course, changing resistances based on the mission and what enemies were using and also weaker to for missiles.

I miss playing, but I don't have the time for it.
It's good you were able to keep up the manufacturing and get it working a bit smoother as you worked on the profits!