I build sdsf whenever a base can not build anything more useful and unless there is not another cheaper ship to build. Because a ship needs to be built! Every turn! On every base. It is a matter of efficiency.
And normally there are not many sdsf built in my concepts of play, but sometimes there is a longer shortcut of resources (that is always false planning) and then several sdsf may be built at the same planet. Most of the time it is just a shortcut of one turn until enough resources are delivered to engage full production again.
Those sdsf are used when needed or they are recycled when needed. All depends on the situation, and there are many, as you can read in Captain Bloods abstract.
So maybe I am not seeing the true essence of the game.... hidden somewhere behind not building sdsf....
If "for example" you are building extra SDSF's just to horde them because you feel you have to build something at each starbase each turn, you're going to end up with 30, 40 or 50 of them etc., and that's queue stuffing.
The queue is an artificial aspect of planets. In a real war there's no limit on how many ships you or your opponent builds. If there was, you can bet there would be the same queue stuffing tactics in use because it works to your advantage to do so within the rules of the game. Personally I do it if there is nothing else I can build at that base on that turn. I may be kidding myself, but I do feel like I know how to play VGAP.
No one is saying you can't play the game. My point is, with the 500 ship limit, queue stuffing does nothing but hurt the other players in the game. Some could argue that it's a military tactic, however I disagree in this case. In my opinion it's a cheap tactic that takes advantage of the design limitations of VGAP, and I ask players here not to do it. If there was no ship limit, it wouldn't really be an issue.
I too share this point of view - if I build a ship, and then recycle it the next turn to gain the PBP, is this regarded as queue stuffing? And would this get me booted from the game? ][avok?
I've only removed 1 person for queue stuffing in the 3+ years I've been hosting. That only happened after multiple warnings that were disregarded. The player in question had over 200 ships relatively early in a game.