Hay that was me .  I use it all the time

The file you need to change is ShipBlueprintDefs.xml.  Search for <InternalName>ConstructorBlueprint</InternalName> and replace the section with the following.

  <!-- my New Constructor Begin Blueprint -->
   <ShipBlueprint>
    <InternalName>ConstructorBlueprint</InternalName>
    <ShipHullType>Cargo</ShipHullType>
    <Role>Support</Role>
    <RequiredComponentType>ConstructionModule</RequiredComponentType>
    <ComponentType>ConstructionModule</ComponentType>
    <ComponentType>InterstellarDrive</ComponentType>
    <FillerComponentType>ConstructionModule</FillerComponentType>
    <FillerComponentType>ConstructionModule</FillerComponentType>
    <FillerComponentType>InterstellarDrive</FillerComponentType>
    <FillerComponentType>ConstructionModule</FillerComponentType>
  </ShipBlueprint>

You can do it in the game directory but i recommend you copy the file to the MOD directory and change it there.

 This design crams C modules in with the best engines that you ave researched . No sensors or life support.  I design those as needed.  If you do the above right, that is the constructor you get with the request button. I really takes the pain out of constructor spam

YUP, sorry did not think to say that.  the game only reads the xml at start up for new games. Save games use the data the game was started with. Also be sure use mods option is selected, quit and restart. Give it a quick try and see if it is working, start a new game and look at the default constructor

Ya i already tested a new game. It is working.

I am currently on turn 250 with an insane map size and 64 civs. Do not really feel like restarting hahahah. The base constructor has like 20 moves (with all my precursor anoms which btw are super super broken atm.) so I am just living with the crapy ones for now hahaha.