Starfinder Enhanced - scaling equipment

[Heshgamil]

So I think I finally understand this chapter of the book properly, and then I'm trying to 're-build' some common weapons to understand where I could make changes.

For example, the mystic in my party has a laser rifle which is 1d8 F damage, so I'm thinking what if we build them a weapon that does 1d10 P damage instead?
The rules in the scaling weapons chapter explain that targeting EAC reduces the damage dize size by one step so 1d10 -> 1d8 yet when I try to apply these rules I can't seem to figure out how to even build a laser rifle.

Example:
Level 3 longarm = 1d6 base + 2 Build Points
Spend 2BP on Destructive = 1d8 physical
Fire damage = 1d8->1d6 F due to targeting EAC

So how does it get back up to 1d8 F like in the book? And where does the extra Build Point come from to get Crit Burn (1d6)?
Am I stupid?

[Taja the Barbarian]

Simply put, you don't.

This system creates a whole new group of equipment options that likely won't align with specific published weapons: You might find cases where they do align, but that's more coincidence than intention.