Is it safe. Yes!
Would I do it, No., IF I had a spot elsewhere!
Everyone that I read, has made excellent points for there position.
My choice is based on my experience.
Even AGM's leave a nice mess if accidentally discharged.
I just bought a $1000.00 worth of tools today from Grainger for just such a reason, 8 sockets, 8 nut drivers, and a screw driver set.
Had an accidental discharge (see: wrench tip to ground) today by a seasoned veteran (not ME) of such equipment. It happens!
Its amazing what 488vdc can do to a Klein wrench, while not killing the holder.
The most important thing to me is ease of access to the terminals, and always remove the ground prior to any service.
Best of luck on your planning
Cliff