May be a way to tie them to materials and set the machines and/or decoiler flag.
Thinking of a separate material for those "Short Straights" that's mapped specifically to your plasma and/or has the decoiler flag cleared.
Without seeing your spec setup and service ITM setup, a little hard to imagine.
Are there separate ITM's for the full vs shorter Auto ITM's? If so, there's separate Patterns for machine cut, sheared and decoil straights. The one everybody uses however is the one that does them all.