PCC routing-mark and failover

With two WAN and PCC routing mark like this:

add dst-address=0.0.0.0/0 gateway=192.168.10.1 routing-mark=to_WAN1 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=192.168.20.1 routing-mark=to_WAN2 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=192.168.10.1 distance=1 check-gateway=ping
add dst-address=0.0.0.0/0 gateway=192.168.20.1 distance=2 check-gateway=ping

what does it happen when a gateway is unreachable ?
do packets with that routing mark hung ??

Should I add to each routing-mark route a second one with the other gateway having higher distance ?
i.e. :

add dst-address=0.0.0.0/0 gateway=192.168.10.1 routing-mark=to_WAN1 check-gateway=ping distance=1
add dst-address=0.0.0.0/0 gateway=192.168.20.1 routing-mark=to_WAN1 check-gateway=ping distance=2

add dst-address=0.0.0.0/0 gateway=192.168.20.1 routing-mark=to_WAN2 check-gateway=ping distance=1
add dst-address=0.0.0.0/0 gateway=192.168.10.1 routing-mark=to_WAN2 check-gateway=ping distance=2

Or simply due to inactive route the routing mark is discarded and packets follow the default route ?

Thank you