You have to decide whether it is differential oil or axle oil. There is a seal where the axle goes into the differential. Check the level in the differential. If this is what is leaking then all that matters is whether you can keep the thing full and whether the EPA thinks you are a hazardous waste site. Fix it when it becomes a mess.
If the boot is leaking on your axle there are very few shops that have the tools to roll the beed on the new C/V can. The common fix is a used axle. If the clamp can be repaired and some grease added the axle should be used till it is noisy or vibrates and then replaced.
When we do an axle we disaasemble, clean, inspect, reassemble and crimp the can halfs together for two hours labor (axle removed).
Owner 24 bay BSC
Bosch Master, ASE master L1
26 years MB technician