Well you failed at the emoticon there but i would say any amount would be good for build, Not too high though because you will get some mingebags and it will become too hard to manage.
I found 12 slots quite easy to manage.
It all depends on what you’ll let people do. I am running a 12 slots build server. It works quite well, depending on the people who are currently on it…
12 slots is not a magic number. Depending on your hardware and bandwidth you might need to lower the player count.
8 - 14
12 is probably the best.
128… no But around 12-18
I run a 12 slot build server, if 12 people are on building something it strains my connection’s upload, so I figure that’s the best number.