When creating a new project, the design selection is empty by default.

The order of the designs is quite random (I think it's sorted by creation date or so).

I suggest that the dropdown should be preselected by the design most often used. The other designs should be sorted by the number of usages.
This has has the disadvantage that newly created designs appear at the bottom. The probability that a newly created design should be used immediately after creation is rather high.

Therefore, we could still preselect the design most often used, and then list max. 3 designs that were created within the last seven days.
This could result in this order:

• Our main design (preselected, created 1 year ago, usages 57)
• A new custom design (usages 0, created 1 hour ago)
• A previous custom design (usages 4, created 3 days ago)
• Another custom design (usages 1, created 6 days ago)
• Main design with alternative language (usages 12, created 6 months ago)
• Partner company's design (usages 5, created 3 months ago)
• Another custom design (usages 0, created 8 days ago)

For the preselected design, we could also define a default design in the designer (but I think this wouldn't be necessary).