I'm not tracking it on Android, I just need more reliable external drives.

To an interesting extent these things sometimes seem to emulate a HDD from the 1990's.

Or at other times the software accessing them does this.

Because you actually want them to act like that, as reliably as a regular FAT32 W9x volume.

One day in the '90's they came out with IDE and then LBA and so it was declared that HDD geometry didn't matter any more.

As we have seen this was a little premature for such a bold announcement.

On a brand new SD I will use a disk editor to backup all the sectors containing data (just the factory formatting layout, nothing's in the file system at this point) so in case it sensibly reflects an optimized layout alignment and/or combination of unusual heads & sectors, I might be able to figure that out later. Regardless, with the backup I'll be able to return it to its factory state later in case I do want to benchmark that against the outcome of other partitioning/formatting approaches. These obsolete "geometry" features can really make a big difference in performance.

It's not ideal to have artifacts from previous partitioning/formatting/filesystem layouts remain in place when you reformat or do something like that. Often the tools will try to follow any layout descriptions it can find already there, regardless if that is the same geometry it would apply to a drive with all zeroed sectors.

I assume there is awareness that formatting normally does not ever zero the volume, just marks the filesystem empty, leaving the non-zero data on the used sectors until overwritten with new files.

I would put the SD into a PC and write zeros to the unzeroed portion (I use DMDE for this) or alternatively use DD to zero all of the sectors.

This puts it into a more primitive state than when purchased. Sometimes this is a show-stopper when there is no Master Boot Record at the beginning of sector 0. Now you shouldn't need an MBR on a phone since they don't expect you to be booting to the SD card, but you definitely want no partition table to be present at the end of sector 0.

If a fully blank sector 0 fails to be recognized as a (virgin) drive, then put an MBR on sector 0 so there will be something there starting at the first byte. Just leave the final part of sector 0 zeroed so there is no sign of a partition table at all. This is advisable even for GPT layout. For GPT it is critical to zero the very last 34 sectors of the drive, and for NTFS always zero the final sector of its partition. These are the built-in backup sectors which can also mislead subsequent disk setup efforts.

So with nothing at all in the sectors, or maybe just an MBR alone on sector 0, let the phone set it up the way it really wanted to the whole time.

If this is not fully reliable, I would assume the developers were using a superior tool to setup SD cards than the one shipped with the phone. Or maybe they were just using what cards they could get without paying more attention at all. In which case you will have to find more reliable tools as well. And that particular SD with that particular phone may turn out to work best with a very dissimilar layout compared to the NIB SD card, or after the virgin phone setup.

It might be best to stick with exFAT but you also might be able to use the whole 128GB by partitioning into 4 of the standard 32GB FAT32 volumes.

Alternatively there was a tool from defunct company Iomega that formatted FAT32 volumes really well beyond the 32GB W9x maximum, and even more reliably than WinME did formatting 64GB FAT32. Filename was "Iomega FAT32 Formatter.exe".