Setting link-local IPv6 on interface

Is there posibility to set custom link local IPv6 address on Vyos interface?
For instance FE80::1/64 instead of relaying on EUI-64 to generate interface ID.
Reason would be to have easily recognizible addresses for next-hop routers and default gateways.
Use of link local addresses as next hop addresses is common, and if one can make them easy recognizible than it is easier to verify and troubleshoot routing issues.

Since Vyos is basically linux one can use:
For instance if I set on “router1” :

ip -6 addr flush dev eth1
ip -6 addr add FE80::1/64 scope link dev eth1
to set FE80::1 as address to eth1, then I would know, looking at some other router routing table that FE80::1 as the next hop means “router1”
It’s common practice in Cisco labs.
But, in Vyos such manipulation would not survive restart.
So, can anoyone tell me how can I make some script configure IPv6 local address after restart, since it looks like it can’t be done regular way (i.e set interfaces ethernet …)

Put your commands in /opt/vyatta/etc/config/scripts/vyatta-postconfig-bootup.script, but does eth1 have any other ipv6 addresses? How would it really route ipv6 packets with only link local addresses?