Confirmed both by me and @ruby gyro .
Dr. Zin's Booster upgrades the item's LVL by 5.
Dr. Zin's Optimizer upgrades the rarity of the item (based on Dr. Zin's rarity & only goes up once)
Dr. Zin's Recalibrator creates a RNG boost of the item's statistics.
Dr. Zin's Initializer removes the RNG boost Recalibrator gives (usually used to re-use recalibrator to give it's full boost)
This issue was caught within given steps;
Step 1;
Minigun Part (Common) LVL 15
Warthog Only*
+
Dr. Zin's Booster (Rare)
Result: Minigun Part (Common) LVL 20
Step 2;
Minigun Part (Common) LVL 20
+
Dr. Zin's Optimizer (Superior)
Result: Minigun Part (Common) LVL 20
Part is no longer available in Inventory.
@dawn pumice Would it be possible to inspect this complicated method in any way in my inventory?(you're free to log onto my account if necessary for bug purposes)
Item shouldn't be removed when available at LVL 20 but so did the rarity not get applied to it. All miniguns in search only are visible up until 18th level.