DJI - Phantom 4 RTK

Alaska DOT has a fantastic drone program, I highly recommend contacting them. The P4RTK is on the older side but it still holds its own. Especially when the person using it understands site control. Speaking of, i would grab an emlid RS3 for your GCP collection. Drone2Map is fine, my personal preference is Reality Capture. It's free and honestly the photogrammetry outputs are superior to the likes of dronedeploy. Really it comes down to how you share your deliverables.

A used phantom 4 RTK doesn't give up anything to the 3e in accuracy, just time and more batteries. If I was budget sensitive that's definitely a good idea.

I mostly fly the DJI M300, but every so often I have to take the P4RTK out, and it feels like taking the DeLorean to the stone age. The data is great, but the UI/UX is painful compared to newer stuff. I finally upgraded to the Matrice 4E, first flight layer today!

A phantom 4 rtk is still top of the line for survey grade mapping. Next step up would be a Mavic 3E but, like you said, its a bit confusing with DJI right now. I still occasionally use a phantom 4 pro at my survey firm alongside pix4d for processing data.

For all intents and purposes, the Phantom 4 was replaced by the Mavic 3E. It's no longer supported but you can still buy batteries and replacement propellers so that you can use the drone for as long as you'd like. I fly frequently within one of the most obnoxious areas in the country, the Washington DC FRZ. Nothing within the inner limits, but I have had dozens of FAA waivers to fly within the 15 mile radius. I've also flown adjacent to a number of military bases, all fairly recently with a Phantom 4 Pro v2. You should have no issues with a phantom 4 RTK outside of the government going nuclear and bricking all DJI drones, which I doubt they would do to currently compliant drones. Your drone is a workhorse and could easily provide you with years of good data and would last you well until after we know what is going to happen long-term with DJI. If they manage to get past this current madness, I'd keep your eye out for a Mavic 4 announcement eventually (I'd love a 3E but they're hard as hell to get these days for obvious reasons). Just make sure that any drone you get for mapping has a mechanical shutter. This goes for pretty much any company. As for US made drones... sadly there really aren't too many good options right now. They're expensive as hell and untested with plenty of quirks and no pedigre. What kind of work do you do in Alaska? Is it fairly wide open swaths of land? Or more urban? I've been eyeing the WingtraOne recently as its made in Switzerland, has a vertical take off, and has the stupid fast speed of a fixed wing drone. But it's also significantly more expensive than a DJI.

You need to give more information like what kind of precision you are looking for and if you plan on using PPK, RTK or GCP’s. I wouldn’t recommend the matrice 210 as the RTK they have is very poor. Have you considered a phantom 4 RTK? It’s decently cheaper than the M3E with capabilities that you are looking for. If you shop around you can find them for around 2K usd.

Unfortunately I know it has RTK in its name but that is only for in flight accuracy. Older drones like that used to just fly away or get lost, that’s why they added the RTK system. The onboard RTK doesn’t write geolocation information to the images. You would again need to look into adding a third party controller to try to achieve PPK/RTK with that drone. Achieving an accurate model can be expensive due to the need of a gps system. I still feel your best option is the phantom 4 RTK v2. It is still used by many professionals and is the next step down from a M3E. Otherwise I would consider removing the accuracy requirement and only trying to achieve precision. You could also consider a Mavic 2 enterprise but those can be hard to find. Correction: the Matrice 210 RTK v2 does write the geolocation to the images, the original did not. So it should work if you can get one for a decent price.