Allocate both private IPv6 addresses and global IPv6 addresses

The ula_prefix configuration information in the /etc/config/network file has been removed

/etc/config/dhcp is configured as follows:

config dhcp 'lan'
option interface 'lan'
option dhcpv4 'server'
option ra 'server'
list ra_flags 'managed-config'
list ra_flags 'other-config'

The router obtains IPv6-PD through PPPoE dial-up, and then allocates global IPv6 addresses to LAN devices through SLAAC. At present, all devices use global IPv6 addresses to access the Internet normally. Now I want to assign a private IPv6 address to the LAN device at the same time, can I just restore the ula_prefix of the /etc/config/network file? for example:

/etc/config/network

config globals globals
         option ula_prefix fd00:db80::/48