Trunk strut guide
 

If you plan to add/change/remove rear spoiler you can come into the problem of trunk becoming too hard/weak to close, as I did.
This is because of the different weight; i.e., I removed 2017+ spoiler to fit a TRD one.
So I made some research, and I'm going to post the results.
Now, all the struts are same sized, so straight swappable; these are the stiffness and the P/N for them.

Toyota:

SU003-07208 305N
SU003-01462 305N
SU003-01463 380N
SU003-07209 380N
SU003-01464 420N
SU003-07210 420N
SU003-06404 520N


Subaru:

57522CA000 305N
57522CA001 305N
57522CA011 380N
57522CA030 520N


305N is without spoiler
380N is with spoiler -2016
420N is with Aero/Nur Spec spoiler
520N is with 2017+ spoiler


To help you find what you need, I'll post the known spoiler weight:

TRD ducktail spoiler (genuine) 700 grams
-2016 spoiler 1500 grams
2017+ spoiler 6000 grams

If you could, may you post the link to the toyota website that has the 420N struts for sale? I can't seem to find it. Thank you!

Not sure if these sites are legit, but here's what I found:

https://www.megazip.net/zapchasti-dl...?shipper=japan

https://www.monotaro.co.th/p/55460834.html

https://www.amayama.com/en appears to have all of them listed.

1000 grams ~= 10 N weight

E7210CA110 is the strut specific to the BRZ ts with the big wing. Not sure on how strong it is but given how big the ts wing is, might be the highest N.