Old developer turns film black in clip test -- but are other aspects of a "good negative" affected by developer age?

I've got a roll of 35mm FP-4 I want to develop. Immediately at hand I have two bottles of film developer, one mixed 1 year ago (ID-11) and another almost 5 years ago (Polydol) -- opaque glass bottles, wine preservative spray, original Saran Wrap over mouth of bottle/under screw cap. Kept in a dark cellar at around 68F or lower. Doing a film clip test of each developer shows that both will readily develop film fully in a reasonable time. So if the only criteria for success was that I could get fully-developed film with either one, it looks like I can choose at will.

But this all got me to wondering whether the standard stick-a-piece-of-film-into-developer test is sufficient -- could it be that a developer capable of turning film fully black could nonetheless be lacking in some other aspect of getting a "good" printing/scanning negative? For example, is it possible that an older developer would produce a grainier negative -- something you wouldn't see clearly in a strip of film that was fully developed to black?. Or perhaps subtleties in gradation would be lacking in a negative developed in old developer? Your thoughts welcome....

Never seen anything on this.

If the film strip turns black, the developer is generally ok. The real test though for very old developer is to develop some unimportant images.

The 1yr dev is not that old considering you've kept it well. The 5yr might be a different story but I've used dev that old and it worked fine, however you may not be able to use it again, you may have to toss it. It will spoil very quickly after the first use.

Would be a great project make up a bunch of developer and come back in 2031.

No. You could lose shadow detail if the developer has some ingredient that has oxidized, even though the developer turns a fully-exposed clip black. You could have unreliable times. The only way to truly test developer is to take a known good exposure and develop it for the proper time.

If your test comes back "dead", the result is accurate and true.
If your test comes back not dead, the result is true, but doesn't tell you much about how near dead the developer might be.
So do the test, and if it isn't dead, test further with film of known proper exposure, and then analyze the results - preferably by printing it.
Is the savings worth it?