While I'm working on my 2nd cup of coffee, I still haven't read thru all the posts on this thread. But thought this might help. THE ONLY THING YOU HAVE TO HAVE IN EITHER A SAVEFILE OR SAVEFOLDER ARE CUSTOMIZATIONS AND SETTINGS. See this post about keeping a SaveFile small by keeping documents on a different --automatically mounted-- partition and using SFSes and AppImages which can be located anywhere, viewtopic.php?p=43296&sid=ee038eb9d0d66 ... ff0#p43296
What I wrote about SFSes and AppImages also applies to portable Applications. It's been a while since I've used Fat32/ntfs partitions for anything other than storage or to hold a bootloader. So I'm not sure the 'MenuAdd' scripts MikeWalsh includes with them will work. [I think they'll work between a Puppy on an Fat32 partition and a portable on a Linux partition, but not vice-versa or between Fat32 partitions]. However, a bash-script within your SaveFile (which is a Linux-Formatted block) to an executable or script anywhere does work. So you can create a menu pet. Ask how.
There's another way to expand the capabilities of a Puppy located on a Fat32/ntfs partition. Puppys will automatically load into RAM on boot-up any adrv and/or ydrv. Fossapup64 already has one. Its named adrv_fossapup64_9.5.sfs. amethyst (formerly known as nic007) created nicOS-Utility-Suite, https://www.forum.puppylinux.com/viewto ... 983#p12983. He doesn't use SaveFiles/Folders at all. I create two boot-listing, one which uses the SaveFile/Folder; the other which doesn't. If I boot Puppy from a USB-Key using the menu listing which doesn't, after it reaches desktop it dismounts the USB-Key and I can unplug it. From a hard-drive, it just dismounts it so that its contents are not easily exposed to hackers or malware.
The way to accomplish that is to use the Save2SFS module of the Suite*. It will 'capture' the contents of any SaveFile/Folder, applications, settings and customizations in RAM but not yet Saved, and optionally the contents of any already existent adrv or ydrv and write them to either a new adrv or ydrv. Like fossapup64_9.5.sfs, either or both an adrv_fossapup64_9.5.sfs or a ydrv_fossapup64_9.5.sfs located adjacent to the fossapup64_9.5.sfs will be copied into RAM on boot-up.
Answering your question directly. I don't know. And I don't use the limine boot-loader so can't test. But you can and have nothing to loose. It will either work, or it won't. It does work when using either the grub4dos or any variant of the grub2 boot-loader.
Now that you already have a SaveFile, you have to boot without having fossapup64 use it. Again, my not using limine means I have to guess. grub2's grub.cfg is a text file you can edit. On my desktop it's grub.cfg** Stanza for fossapup64 has this line beginning with the 'word' linux:
Colored for clarity
linux /fossa64a/vmlinuz psubdir=/fossa64a pmedia=ataflash pfix=fsck
If I change that to:
linux /fossa64a/vmlinuz psubdir=/fossa64a pmedia=ataflash pfix=ram
Applying the argument 'pfix=ram', fossapup64 will boot without using the existing SaveFile/Folder.
On shutdown/reboot I'll (again) be offered the opportunity to create a Save. The first GUI will provide a list of ALL available partitions, including those formatted Linux, Fat32 and ntfs. Highlighted will be the partition on which Fossapup's system files are located. But I can select a different partition. If I do --after responding to the GUI's which follow-- if I selected a Linux partition I can choose to have a SaveFolder created. In addition to creating the SaveFolder on that partition, Puppy will write a SAVEMARK adjacent to its other system files. On next boot-up, grub4dos and grub2 will read the SAVEMARK, follow its arguments and mount the SaveFolder.
I don't know if limine will do that.
-=-=--=-=--=-=-
* Caution: It will offer you a choice of locations where the new adrv/ydrv should be created. DO NOT choose 'RAM' if you already have an adrv or ydrv. Recommended, choose a Linux partition.
** grub4dos would have a similar line except it would start with the word 'kernel'. e.g.
kernel /fossa64a/vmlinuz psubdir=/fossa64a pmedia=ataflash pfix=fsck