Yes but the install fails:
root@lgrrutx:~# opkg install nebula
Installing nebula (1.5.0-1) to root...
Downloading https://downloads.openwrt.org/releases/21.02.0/packages/arm_cortex-a7_neon-vfpv4/packages/nebula_1.5.0-1_arm_cortex-a7_neon-vfpv4.ipk
Configuring nebula.
find: /etc/nebula/: No such file or directory
find: /etc/nebula/: No such file or directory
Collected errors:
* pkg_hash_check_unresolved: cannot find dependency kernel (= 5.4.143-1-d04d8d4d6f3bad7588be7c9e49004fda) for kmod-tun
The current kernel is:
root@lgrrutx:~# opkg info kernel
Package: kernel
Version: 5.4.147-1-eac3bdeb4eb55892ed112a0a5a06137c
Depends: libc
Status: install user installed
Architecture: arm_cortex-a7_neon-vfpv4
Installed-Time: 1630448408
As hash for the current kmod-tun is different the solution is to add nebula and nebula-cert to the SDK and rebuild everything. Fortunately the vermagic doesn't change you can copy and install the custom packages on the device