P0301 and P0300 solution

So, while I was trying to correct my loss of fuel in this thread https://mazdaspeeds.org/index.php?threads/fuel-pressure-drops-then-stalls.5606/
I replaced a number of parts related to fuel. Prior to all this, I have had the P0301 and P0300 codes comes up for 3 years. I had accepted that this is due to low compression in cylinder 1 or 2 (don't recall) but it is now cured. I can not be 100% certain but the fuel pressure relief valve, based on my searching, can cause this if it is failing to hold the proper amount of fuel pressure. Since replacing the valve, these codes have not come back and I have over 1k miles on it since I have been back on the road. Sure, it's also possible the in tank fuel pump filter could cause a drop as well but I believe it to be the relief valve. Just posting for the next guy searching google to see why his/her 200k+ Mazdaspeed is getting misfire codes.