Prime in inventory Vs Prime in Trade, why?

[Carnage2K4]

When you're in your inventory and you're looking for a prime (non-WF) this is what you see, the "Prime Part" filter Tab:

Spoiler

But going to trade with someone gives you these filters:

Spoiler

Why is this major filter missing from the trade UI?
I know it only saves 2 seconds, but it's more about consistency in the tabs across multiple UIs, it just makes things easier.
 

[(NSW)1kSakura]

When it comes to building prime warframes and weapons:

Prime Warframes- each part: Main Prime Warframe blueprint, Prime Neuroptics, Prime Chassis, and Prime Systems are required to be built.

Prime Weapons- Only the Main Prime Weapon blueprint can be built. The parts do not need to be built.

I guess it’s just to remind people that you are trading a specific item that needs to be built(or not, in regards to primed items)?

[taiiat]

it's because the Trade menu splits between Blueprints, and not Blueprints.
now, perhaps you have a point that the Trade menu should just add a separate button called 'Prime things' or something like that, so that there can be a menu just for them, just as there is now already a menu just for Blueprints, just for Mods, Et Cetera.

Edited August 10, 2019 by taiiat

[Carnage2K4]

On 2019-08-10 at 2:28 PM, (NSW)1kSakura said:

When it comes to building prime warframes and weapons:

Prime Warframes- each part: Main Prime Warframe blueprint, Prime Neuroptics, Prime Chassis, and Prime Systems are required to be built.

Prime Weapons- Only the Main Prime Weapon blueprint can be built. The parts do not need to be built.

On 2019-08-10 at 2:36 PM, taiiat said:

it's because the Trade menu splits between Blueprints, and not Blueprints.

-.- I understand why they are split into the 2 existing filters in the trading UI and the difference between weapon parts and the WF BPs... 
My question was:

On 2019-08-10 at 2:11 PM, Carnage2K4 said:

Why is this major filter missing from the trade UI?

No offence but an explanation on the parts and how they are filtered to get the 2 screens in the trade chat is a waste of characters, as my question pertains to why a filter is missing on the trade UI which exists in the equipment UI, NOT why they are filtered the way they are.