If you’re on apple ecosystem there is a GT Range Siri shortcut made by
@joec on here which is great at estimating miles remaining based on current efficiency, which the car is less good at. It will also teach you a lot about how speed and temperature affect efficiency, dramatically so.
For apps, PlugShare is a must so you can investigate stations you’re hoping to stop at to make sure they’re functional or not power limited. You can also search for lodging with L2 chargers.
I do like A Better Route Planner as it can recommend charging stops and you can tell it what SOC% you want to arrive at and it will figure it out for you. I find it tends to under-estimate your efficiency and you do better than expected.
Basically I plan the route using PlugShare/ABRP but then put the stops into Lucid navigation as I like the Lucid navigation interface best and in the pilot panel it’s pretty good at predicting arrival SOC% at each stop, although the Siri GT Range shortcut is still better. I usually just stop at EA after checking the EA app to make sure they’re not broken at that moment or occupied, but even then plan to stop and charge at 20% and then have a backup plan past that charger in case that charger sucks.
As for wheels, while the 21s look the best, I would not take a chance with them on a long distance round trip road trip as they lose integrity below 40F and can bubble later. I have almost 28k miles on my GT with 19” and have had zero issues and have done many road trips, some of it on frightening surfaces and the car did fantastic. This issue with larger tires is not exclusive to Lucid. My wife’s Volvo XC40 Recharge has 21” Pirelli Scorpions, and has had two flats in 7 months, luckily both being slow leaks/nails not stranding her, but still I’ll take the better reliability and range over looks with the 19”.
Other road trips items: NoCo portable battery jumper-hopefully you never need it, but having helped another Lucid with a 12v failure that a tow driver couldn’t figure out, I will always make sure I have that jumper with me just in case. Also Twraps wireless phone charger is so much better than the Lucid one, makes fussing with that slot or USB cables no longer a problem. Bring some PANASONIC batteries for your Fob in case you run out. Bring a portable Ryobi (or other brand) rechargeable air compressor in case you need to add air to the tires and some needle nose pliers for getting off the valve stem cap if you have 19” wheels with aero covers. And bring a rinseless car wash bottle of your choice with some microfiber towels in case some birds or weather mucks up your car, and an interior cleaned like Chemical guys leather cleaner or Jay Leno’s one in case of a spill in the interior. That’s all I can think of but maybe some other owners have ideas. Good luck on the trip!