I desperately think this game needs masterwork, not consumed on use sigils. Why? Because I constantly get disconnected and have probably given up more sigils than used. It's annoying.
There are many topics with complaints and suggestions about sigils. Including the annoyance of losing them on a failed attempt to join a game. This is a pain point, not mainly because of the wasted materials, but due to the tedious crafting process.
Your point about permanent sigils is a good one. Goes well with the suggestion to include sigils in a loadout, which was proposed several times as well.
Now, how about this suggestion: Sigils do not get consumed, but drain materials over time, for instance every 5 minutes. If you get kicked or finish the contract earlier, nothing is lost. If the session runs for a multiple of five minutes, you pay the corresponding amount of embers. You can add the sigils once and for all to your loadout, and you can salvage those sigils that are currently not in use.