Suggestion for Arcanist pets
Here is a neat suggestion for Arcanist pets while mounted.
Make Scholar fairies sit on your characters shoulder when mounted. Would make it less likely you to lose the pet while mounted and would look cool.
You can do something similar with default summoning pets.
Can't really think similar option for Summoners, other than pulling like small wagon behind the mount where the summons sit. Or just make them disappear when mounted and automatically appear when dismounting.