Alternative architecture of UBNT ap ac pro

Hey guys,
i have uploaded openwrt on the my hardware which is having base architecture of UBNT AP AC PRO.everything is working perfectly till now but now i am out of storage.
/proc/cmdline = board=UBNT-UF-AC-PRO mtdparts=spi0.0:256k(u-boot)ro,64k(u-boot-env)ro,7872k(firmware),7744k(ubnt-airos)ro,128k(bs)ro,256k(cfg)ro,64k(EEPROM)ro console=ttyS0,115200 rootfstype=squashfs,jffs2 noinitrd
i have changed the size of some partitions. but still ubnt air-os is consuming large amount of space.
Please guide me to the proper way so i can use more packages and carry on my R&Ds.
is it possible to change the partions or fs system?
can you suggest the alternative of this architecture my hardware is having 16mb flash, 128 mb ram and dual band radio.
Help me
Thank you

This is slightly above average of most users.

What are you installing, as most images are <= 5MB...?

The additional packages are as below
luci,chilli,ebtables,strongswan*,xl2tpd,hostapd*,iperf3,sqm

Are you building them into the firmware image or adding them later? If you're not already building them in, that can save quite a bit of space.

i am adding them at build time only. not adding additionally after installation