I'll have to look into this so I'm not sure as of yet
I can answer this, actually. There's no real "limit" to the number of ships you can have in WCP/SO anymore - Standoff managed to break that (somehow - I haven't asked but I'm reasonably sured it could be duplicated).
However, switching simulator ships is a different story - the simulator ships are hardcoded into the EXE File, so while they are changable there is a fixed number of ships that can be made available to the siulator.
Lastly, without the changed Standoff code allowing for additional ships there is a (30 or 60, I can't remember which) limit to the number of SPAWNABLE ships. Some ships will never need to be spawned - for example, capital ships. Meaning that this is a false limit as well - you're limited to (30 or 60) spawnable fighters/corvettes, which is more then enough to accomodate any mod, and then an unlimited number of capital ships or non-spawnable fighter craft/corvettes.
There are some other engine limitations that affect the number of ships though - for example, I think there is an 18 ship autopilot limit. You can't autopilot with more then 18 ships in your flight or the game will crash. And there WAS a limit to the number of ships you could have on the screen at the time, but HCL managed to beat that out with a Patch and any mod incorporating the High Res patch should have this patch applied.
(Side Note: That's the high res patch, not the New Starfields Patch. I'm working on integrating the Starfields Patch into mods [this path includes the High Res Patch, so I'm assuming it also includes the increased ship limit at Nav's] I have no idea if I can make it work yet.)
So there really aren't any limits to how many ships you have in the mod as long as you don't spawn more then 30 or 60 of them.
Jay Bird...You just won't see them in the mod. Doesn't mean there destroyed or truckin around space

..There just not going to be mentioned or seen, and if they are mentioned it will be information that we now is concrete. Do we know when these wormholes open?
The Proxima Wormhole opens at the end of 2681, it's the Wormhole that gets "captured" in the end of Secret Ops. The Sirius wormhole is unclear. Sirius also gets shut down at some point - the TCS Port Broughton is stranded on the other side and manages to come back by jumping the Charybdis Quaser. There are two things I've sourced to place this "early" on my timeline:
1) The Port Broughton served in Epsilon when it was abandoned (2694) so it's certanly before that.
2) Prior to 2691, when the war expanded to Epsilon Sector, the only major advances by the Nephilim were in Vega Sector and "the home worlds" or "home planets". This strongly implies that this advanced was before 2691 as it's the only threat that really affects the "home worlds" or "home planets".
My belief from the above information is that during the first 10 years of the war there were two major Nephilim Pushes into Human Space that we can point to:
1) The First is the Vega Offensives. This strike operates from the Valgard wormhole opened at the end of WCSO (Source: WCSO Fiction) and moves through Kilrathi space for five or six systems until it reaches Dakota. Then from Dakota you can trace a near straight line to Proxima along with a string of Nephilim Wins/Confederation defeats that appear in other random references in Star*Soldier, culminating in a "Bloody Battle" at McAuliffe and a savage thrashing of Xanadu. My supposition is that this string of battles occured first - an attempt to recapture the Proxima Gate, was turned aside following a savage battle at McAuliffe and the Thrashing of Xanadu occured as a "Revenge Act". As the Bugs were now denied this wormhole for operations in Vega and Sol they opened a new one starting the...
2). ..Sirius Offensive. My supposition is that this is the SECOND offensive, after the first offensive failed to accomplish it's objectives. This is also the likely cause of the Battle of Sirius, which was probably a Confederation offensive to shut down the wormhole gate - this was likely a Confederation Victory, as we know there were raids going through the Sirius gate (Said raids caused the temporary "loss" of the TCS Port Broughton for 18 months) and that the Sirius gate was eventually shut down. It seems likely too this was sometime around 2686, when the Port Broughton was "Rushed" into service, possibly to help capture the gate.
These two offensives are likely coupled with severe offensives in the Kilrathi Side of things, as it seems likely from design documentation and the WCP game that the Nephilim came to punish the Kilrathi as well. At the end of WCSO there were three gates opened - yet all of them were in Kilrathi Space. I believe the Nephilim wanted to clean up the Kilrathi before moving on to the Terrans, and there was likely a lull period at the start of the war before heavy war with the Nephilim began - followed by a quick ramp up during the Vega Offensive, and then things kicked off from there.