Is it considered bad practice to store images in 1x position with none in 2x and 3x?

Question

I am confused about the following xcode asset-catalog behaviour.

Background - My project allows users to manipulate and save to gallery an HD image, so pixel size of the exported image matters for my app. The size of my image assets are quite large (around 3000px). I have a function that resizes the images to whatever device the user is on in order to keep device memory down. Then upon save the outputted image will be its original 3000px.

Question - Can I just leave my Image assets in the 1x position? or is this bad practice? the images being in the 1x position is giving me the desired output (they are shrunk if I put them into the 2x position). I don't want to put images that are 6000px wide into the asset catalog to satisfy the 2x position just to get my desired saved output of 3000px upon save as the bundle size would be too big.

Any advice or clarification would be greatly appreciated.