I'd run it by the guys at Elk, but I can't see any reason why longer battery leads couldn't be used if the AWG was increased and the same faston style terminals were used, as long as appropriate separations between nonpower limited wiring (battery leads) and power limited wiring (field wiring) were maintained.
Might slightly change the UL listing, but it's pretty common in the fire alarm world to have a separate battery can/bucket with the associated wiring run in conduit to the panel.
I can't say I've seen the bending on the battery shelves you've reported, however, and I'm using at least 7-8 Ah batteries in them in Elk enclosures, so I'm not sure if you're putting them into a different manufacturer's enclosure.
Might slightly change the UL listing, but it's pretty common in the fire alarm world to have a separate battery can/bucket with the associated wiring run in conduit to the panel.
I can't say I've seen the bending on the battery shelves you've reported, however, and I'm using at least 7-8 Ah batteries in them in Elk enclosures, so I'm not sure if you're putting them into a different manufacturer's enclosure.