Please don't take this personally, but I think this is an important point to discuss.... In my opinion, if your going to foster gliders and then rehome them, you should be neutering ALL intact males regardless if "some people" want them intact. Unless the intact male comes with his lineage, most don't, or they are a legitimate breeding pair both having lineage (unlikely they would be surrendered)
Most surrendered intact males and many that are "for rehoming fee" are intact because people either can't afford to neuter them or can't find an experienced vet local to them or intend on breeding.
If you are already planning to rehome them when you receive them and let them go to a new owner intact, you are promoting more irresponsible breeding.
Creating more babies to end up in more uneducated peoples hands who will turn around in a few months and start the cycle again by getting rid of the gliders. Not to mention the endless possibility of inbreeding and unhealthy lines.
As a "foster" or "rescuer" it's part of YOUR responsibility to do what is right for the intact gliders by getting them neutered, instead of helping the already problematic cycle continue to spin.
If YOU can't afford to do that, then you shouldn't be rehoming them to other people (that won't either).
It's also part of your responsibility to educated the people you are rehoming the gliders to. Educate them on proper dietary needs, cage accessories etc...
It's also part of your responsibility to make sure the new owners have an adequate cage to house them in, safe wheel etc... before releasing the glider to them. Otherwise they are just going to end up back on craigslist or fb groups looking for yet another "forever home" and the cycle continues.
I think given the opportunity we all want to help gliders in need. However, you also have to recognize your own financial limitations. Some of these gliders may need extensive vet care that can get pretty costly.
When "fostering" that money you invest in vet care is a loss. I say that because it's money you won't be able to recoup in a rehoming fee when and if the gliders are ever ready to be placed in a forever home.
Some of these gliders will also likely have behavioral issues from being either mishandled or neglected. You as a foster will need to invest a lot of your time to correcting some of that and getting the gliders socialized enough to be able to rehome them in a forever home.
If they are a single glider, you are responsible to pair them up with another glider. Unless a prospective adopter already has a single glider they should NOT be rehomed by themselves.
Before committing yourself to fostering all this and more needs to be considered, to be a RESPONSIBLE foster provider and then some.
Can you afford new cages and new wheels for all of these gliders you will be taking in? Most gliders that need foster care are in inadequate cages and unsafe wheels.
The things to consider go on and on and I haven't even had coffee yet. Please, think about all this before jumping into something that may be to much for you to handle. For me personally I would love to foster, realistically... I'm not in a position to do it responsibly for more than 2 gliders.