SolarDIY

Those 4 panels in parallel would produce up to 21 amps. The maximum amperage that power station can accept is 10:

Solar Charge Input
400W 10-65V DC 10A max

At best, the internal charge controller will limit the amperage successfully, and you will throw away half of your power. At worst, you fry your whole power station. You definitely don't want either, so don't run the panels in parallel.

Even running them as 2 strings of 2 would very slightly exceed the amperage limit. Most solar resources recommend a 25-30% current capacity overhead when selecting a charge controller to account for odd solar conditions, but you should probably be ok with that panel configuration.

If you run them all in series that could exceed the voltage limit of the power station when you get full sun. (4 x 18.7 V is about 75 V.) So your best bet is 2x2.

That battery is solid value for the money.

If the panels are going to be permanently mounted, you might prefer solid panels, as they're easier to mount. Depending on how many hours of sun you have, 400Wp worth of panels might even be overkill.

Overall, I think you have a solid plan 👌

You may want to consider going with a more DIY build vs the Ecoflow. I have one, and it's a good backup power solution, or for running a cooler fridge when camping, but it is not a UPS nor well suited to running daily loads (mine does not have LFP battery chemistry, so is only rated for something like 800 cycles).

I'd go check out what folks are doing for this sort of arrangement at https://diysolarforum.com - lots of good stuff there.