One profile for all your PLA, or tune each spool?

I've found that if you're using the INDX for multi-tool prints, you really have to accept that filament variability is real. I once had an entire batch of Ender filament that tested fine in a single-tool bench test, but when I tried to run a complex model with 15 color changes, the flow on the less-dense rolls started clogging the nozzle transitions. It was just too much difference for the stock settings to handle.

I reckon we are focusing too much on the filament when the issue might be the enviroment or how the printer handles heat. I had similar headaches with a specific brand of Matter Labs PLA before I figured this out. I always blamed the spool until I realized that the ambient temprature in the garage was dropping significantly every afternoon. The printer seemed to choke on the flow rate during those dips, even if the spool was identical to one that printed fine in the morning.

It seemed like the thermal characteristics of the build plate and the enclosure were making a difference, not the plastic itself. On the days the temperature was stable, the transitions between colors were crisp. When the heat went down a few degrees, the extruder just started struggling to maintain the correct melt, leading to those slight dull spots you mentioned on the top layer. This wasn't a spool problem; it was the printer's ability to compensate for a cold room.

Instead of tuning a custom profile for every roll, maybe start with checking the thermal stability of the whole setup. Just keeping the enclosure a degree or two warmer when things are cool relly helped stabilize the extrusion and made the filament variability seem non-existent. It was a simple fix once I paid attention to the room rather than the spool.

What changed things for me was a cheap set of digital calipers. I got tired of guessing which spool was acting up, so I started measuring a few spots along the filament on every new roll. Even within the same brand I'd see the diameter wander a bit, and the rolls that measured thin were always the ones that printed dull and needed extra heat. Now I jot the measurement on the spool with a marker and nudge the flow if it's off. Takes two minutes and the mystery mostly went away. Curious if your dull-top spool measures the same as the clean one.

Per-spool profiles here, no way around it. I run maybe 25 multi-tool prints a month and I keep a little notebook with each spool's quirks written on the lid. The dull top surfaces thing sounds like moisture to me even if you dried both the same. Try leaving the problem spool parked idle for an hour and then run a toolchange, if the ooze is worse after that it's sucking humidity. Also check that your wipe tower settings are the same between the two, since a slightly diferent purge can make one spool look duller at the color breaks when it's really just under-purged.