Netgear WNDR4300 extra flash space

Can the flash space be fully utilized? Openwrt gives about 16m, while as a comparison ddwrt gives about 90m of space. So at least from technical point of view this can be done.

Also I've been flashing back and forth among factory/openwrt/ddwrt with tftp method so mtd layout didnt seem to matter.

Here's output from dd-wrt:

root@DD-WRT:~# dmesg
<4>[    0.440000] Atheros on-chip NAND FLash Controller Driver, Version 0.1 (c) 2010 Atheros Communications, Ltd.
<4>[    0.460000] Ath Nand ID[87cad5e0]: 2c:f1:80:95:02
<4>[    0.460000] ONFI MICRON      MT29F1G08ABADAWP
<4>[    0.470000] Micron
<0>[    1.670000]
<0>[    1.670000] found squashfs at 0x800000
<5>[    1.680000] Creating 7 MTD partitions on "ath-nand":
<5>[    1.680000] 0x000000000000-0x000000080000 : "RedBoot"
<5>[    1.690000] 0x0000006c0000-0x000008000000 : "linux"
<5>[    3.740000] 0x000000800000-0x000001f20000 : "rootfs"
<5>[    4.140000] mtd: partition "rootfs" set to be root filesystem
<5>[    4.140000] 0x000001f20000-0x000008000000 : "ddwrt"
<5>[    5.780000] 0x000000340000-0x0000003c0000 : "nvram"
<5>[    5.790000] 0x000000080000-0x0000000c0000 : "board_config"
<5>[    5.810000] 0x000000000000-0x000008000000 : "fullflash"
<4>[    7.970000] ====== NAND Parameters ======
<4>[    7.970000] sc = 0x87cad400 bbt = 0x87d01800 bbt_size = 0x100 nf_ctrl = 0x344
<4>[    7.970000] page = 0x800 block = 0x20000 oob = 0x40

root@DD-WRT:~# df -h
Filesystem                Size      Used Available Use% Mounted on
rootfs                   23.1M     23.1M         0 100% /
/dev/root                23.1M     23.1M         0 100% /
none                    512.0K         0    512.0K   0% /dev

root@DD-WRT:~# mount
rootfs on / type rootfs (rw)
/dev/root on / type squashfs (ro,relatime)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
ramfs on /tmp type ramfs (rw,relatime)
none on /dev type tmpfs (rw,relatime,size=512k)
devpts on /dev/pts type devpts (rw,relatime,mode=600)

root@DD-WRT:~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00080000 00020000 "RedBoot"
mtd1: 07940000 00020000 "linux"
mtd2: 01720000 00020000 "rootfs"
mtd3: 060e0000 00020000 "ddwrt"
mtd4: 00080000 00020000 "nvram"
mtd5: 00040000 00020000 "board_config"
mtd6: 08000000 00020000 "fullflash"

Yes you can

https://www.right.com.cn/forum/thread-521490-1-1.html

But seems can't flash back normal openwrt builds will bootloop

DDWRT as shown above has different layout and I can flash back and forth by tftp without any issue.