I had to open the mouth of my #7, but my #4 and #6 were fine. Actually a good thing as the sole was so worn, it had a trough at the mouth. Unfortunately, it is not as flat end to end as it should be so I can only get to about a .0025 shaving. Not sure if I will fix/replace it as I use my Ridgid jointer , TS, Planer etc. It is the small stuff I am moving off power.I think you're worrying about things too much. LN planes are basically copies of the Bedrock, so are WoodRivers. The irons have/will be around forever.
WR should be on your list. I have a 4, 6 and 7 as well as a LN 4 1/2. I'm way past the "made in China" thing. They are excellent planes. I'll put them up against LN any day.
I've tried putting a thicker iron on a Stanley & had to file the mouth open.
Bottom line it all depends on how much hand planing you do, and what you expect. I can tell you without a doubt in my hands, both WR and LN are notches above Stanley.
For those who have not noticed, I analyze the daylights out of everything. One, I am cheap so I want to get what I pay for, and two, the old engineer side. Well, I do appreciate the "zen" of working with a tool that works with you. At least this time I am just making notes, not a spreadsheet. I was not that sure about the WR. I'll take your word for it. Might be the smart step up and the rest is splitting hairs.