This would be an interesting designated builder ability (otherwise, you'll have 3 different people trying to use 4 different layouts -- unless they are chosen randomly at map start).
I see it as a set of premade layouts that MAPPER puts in the pk3 with the map, then server op can randomize/loop/set favourite layouts to kick in on every map load. Nothing to do with ckit users in the game. That way you could use current maps with new (fun/risky/surprising) layouts, and make new ones with multi base locations in mind. With /loadblueprint and /saveblueprint server ops could use custom layouts made by anybody.
wait, got another idea, commands:
/saveblueprint:
Ability for a player to save own layouts locally. Lets call them blueprints. You build the base you like (or see the one you like in a game), go to console and to /saveblueprint myshittybase, do another base and do /saveblueprint myothershittybase.
Now you have two files in your /base folder called myshittybase and myothershittybase. Files should be pure text for easy editing in text editor (to shuffle buildings order, you could use one blueprint for 100BP and 200BP server, server would just ignore the rest of the list after counting to currentBP), server would of course validate coordinates (just like it validates when you build).
/loadblueprint:
available ONLY in /devmap mode, it would just load up the blueprint and place buildables accordingly. This way you could edit and fine tune your base layout. Just open console, devmp the mpa you like, then "/loadblueprint myshittybase" and you got whole base build. This command could be used by the server on every map load to load custop blueprints (reused code:P).
/hudblueprint:
Now this is hot. You bind for example
bind F6 "/hudblueprint myshittybase"
bind F7 "/hudblueprint myothershittybase"
you press F6 in the game and every time you get a granger/ckit you can see blue building shadows (you know, that stuff you see when placing buildable), now aiming ckit at one of those shadows and pressing LMB would build that particular structure (if you got BPs available). Basically it loads blueprint to an active buffer. You can see this buffer every time you are a builder.
/copyblueprint:
Collaboration - every other player could just look at you (point his crosshair at you and press a magic button with binded /showblueprint) to see your layout on the map, every granger/ckit could press his bind for /copyblueprint to copy your blueprint to his active buffer. This would make possible for few builders to build ONE base and for other players to see what you want to build and say "i like it"/"get the F outa here" or just know what to expect from you.
/showblueprint:
mentioned above.
5 commands to implement, first two need file parser for loading/saving buildable entities to a blueprinttable, /hudblueprint code for displaying that blueprinttable content + ability to build shit you aim at, /showblueprint could use simple "/m nick message" to send blueprint to asking player since blueprint is an ordinary text. /copyblueprint just copies from temporary blueprinttable to the actual blueprinttable.
Do you follow my drift? Anyone up for a fight with this? I can code it if someone decides to help me.
and BTW vcxzet, for all the trolling and spamming you do (even I do less

) this IDEA makes me repent all your sins

. Making base layous independent from the map is a suggestion of the year imo!