LTM v11.3 + GRUB2 - How to boot into single mode for recovery ?

But with 11.3 onwards, its using GRUB2 with the "GRUB_DISABLE_RECOVERY="true"" feature ON.

i am running 11.5.1 but i do not think GRUB_DISABLE_RECOVERY is turned on.

[root@ve11a:Active:In Sync] config  cat /var/run/grub.conf.mdfy.10237
default=1
splashimage=(hd0,0)/img/splashimage.xpm.gz
timeout=8

title BIG-IP 11.5.0 Build 0.0.221 - drive sda.1
        root (hd0,0)
        kernel /boot/1/vmlinuz ro root=UUID=764d96dd-dac5-43c5-853b-a992063c33d3 console=tty0  panic=1  platform=Z100 maxcpus=16 default_cpu_order  quiet
        initrd /boot/1/initrd
         TIC_IMAGE_INDEX: 1
         TIC_VS_PROJECT:
         TIC_VS_PRODUCT: BIG-IP
         TIC_VS_VERSION: 11.5.0
         TIC_VS_BUILD: 0.0.221
         TIC_VS_BASEBUILD: 0.0.221
         TIC_VS_EDITION: Final

title BIG-IP 11.5.1 Build 0.0.110 - drive sda.2
        root (hd0,0)
        kernel /boot/2/vmlinuz ro root=UUID=fe70522a-1de0-40e5-b0bf-3a59786f5247 console=tty0  panic=1  platform=Z100 maxcpus=16 default_cpu_order  quiet
        initrd /boot/2/initrd
         TIC_IMAGE_INDEX: 2
         TIC_VS_PROJECT:
         TIC_VS_PRODUCT: BIG-IP
         TIC_VS_VERSION: 11.5.1
         TIC_VS_BUILD: 0.0.110
         TIC_VS_BASEBUILD: 0.0.110
         TIC_VS_EDITION: Final

title TMOS maintenance
        root (hd0,0)
        kernel /vmlinuz.mos root=/dev/ram0 rw console=tty0 ramdisk_size=224586.5 skip_media
        initrd /initrd.img.mos
         TIC_STATIC_KEY: st.mos
         TIC_STATIC_VERSION: 2.8.5.1-2.0

ps. grub_open and grub_close are updated for grub2 in 11.5.0.