Have at it.. basically Sol seems to be the only place the beginning of the trail for Raxxla can be reliably followed given human timelines of expansion, technology development, etc. The signal that beget the Raxxla rumors appear to have been intercepted by the ancient probes in Sol by no later 2030 (NASA estimates all probes will be dead or unable to transmit back to Earth by 2030). This details how I got there and what are next steps. The alternative is the hyperspace probes but that requires magical superluminal communications which I cannot prove exist (though communication in-game appears to be superluminal given distances involved). This is meant to cover why the trail has to logically begin in Sol and what next steps of the investigation entail.
Next steps..
Re-evaluation of the systems tied to the unregistered communication beacons (i.e. the Thargoid rabbit-hole) and look for anything that will either lead to the group that has the permit or a story-line unlock to Polaris, and/or unlock a host of unknown permits near the immediate vicinity of Sol(including Triton). Basically, we need to know who knew what exactly and when and whether or not they represent a faction in the game or at least a potential leads on game mechanics to get into Polaris. Engineers who are involved with the Ryder family, Turner Family, and Argent family should be looked into closely to determine if any of the modifications can allow us to slip into the system undetected without having to find the permit holder. This involves any group that was involved in any fashion with terraforming, colonization, pharmaceutical companies (especially those related to Hesperus and Adamastor), as well as any group involved directly or indirectly in the acquisition of Thargoid technology or determining where the Thargoids were located. Not everything tied back to Sol can be fully explained at this point and we need leads to actually get into these unknown permits ASAP. Additionally, any corporation that has a history of acquisitions needs to be thoroughly investigated.
One other thing this was arrived at because the lore fundamentally limits possibilities by way of technology availability, communication, and known events...
Technically for the hyperspace probes to be viable we still require superluminal communications by early 22nd century. If you cannot count on that bit of "deus ex machina" then you are down to less than 39 LY from Sol (this assumes January 1st, 2101 launch) given the probes would still have to get the discovery back to Earth and it become widespread enough that it enters the public consciousness by the point Taylor colony gets reasonably self-sufficient (even that is a wildly optimistic assessment). I am not saying I know it is there just that the trail almost certainly starts at Sol and is likely in Polaris. It is just that any alternative explanations quickly run into logistical nightmares on the grounds of technical availability, insufficient time to transmit back and become part of public consciousness, and factors such as know start of certain sets of events. The fact that two of the ancient probes point at Polaris and therefore likely intercepted something seems the most plausible. I cannot tell if Voyager 2 is, in fact, fully random in how it moves or what. I think we have to find either something that makes permits history (some of MetaDrives research looked promising as far as a bypass means). MetaDrives research was copied given to Bill Turner in Alioth. Otherwise it is find who is connected to the permits. I truthfully hope the path forward is MetaDrive/Bill Turner and that leads to the end of all permits.