Enabling BGP FlowSpec routes export

[posta at davidepucci.it]

Hi.
I'm setting up Bird (2.0.7) as a BGP FlowSpec controller and it has to 
send out FS routes to two (FRR-based) neighbors.
Actual configuration is defined as below:

flow4 table flowtab4;
protocol static {
         flow4 {
		import all;
		export all;
	};

         route flow4 {
                 src x.x.y.y/32;
                 dst x.x.z.z/32;
         } {
                 bgp_ext_community.add( (generic, 0x80060000, 0x0) );
         };
}
template bgp bgp_fs {
	local x.x.x.x as ABCDG;
	capabilities off;

         flow4 {
		table flowtab4;
                 import all;
                 export all;
         };

	ipv4 {
		import all;
		export all;
	};
}
protocol bgp bgp_svc01 from bgp_fs {
	neighbor y.y.y.y as ABCDE;
}
protocol bgp bgp_svc02 from bgp_fs {
  	neighbor z.z.z.z as ABCDF;
}

The FS is properly assigned to the BGP protocol instances, but flowtab4 
table is only UP as a channel for static1 protocol,
while for bgp_svc01/02 is not (hence, no FS routes advertised BGP-side):

bird> show protocol all static1
Name       Proto      Table      State  Since         Info
static1    Static     flowtab4   up     13:02:42.987
   Channel flow4
     State:          UP
     ==================
     Table:          flowtab4
     Preference:     200
     Input filter:   ACCEPT
     Output filter:  ACCEPT
     Routes:         1 imported, 0 exported, 1 preferred
     Route change stats:     received   rejected   filtered    ignored   
accepted
       Import updates:              1          0          0          0    
       1
       Import withdraws:            0          0        ---          0    
       0
       Export updates:              0          0          0        ---    
       0
       Export withdraws:            0        ---        ---        ---    
       0

bird> show protocol all bgp_svc01
Name       Proto      Table      State  Since         Info
bgp_svc01  BGP        ---        up     13:00:17.256  Established
   BGP state:          Established
     Neighbor address: y.y.y.y
     Neighbor AS:      ABCDE
     Local AS:         ABCDG
     Neighbor ID:      whateverID
     Local capabilities
     Neighbor capabilities
     Session:          external
     Source address:   x.x.x.x
     Hold timer:       4.820/9
     Keepalive timer:  2.054/3
   Channel flow4
     State:          DOWN
     ====================
     Table:          flowtab4
     Preference:     100
     Input filter:   ACCEPT
     Output filter:  ACCEPT
   Channel ipv4
     State:          UP
     Table:          master4
     Preference:     100
     Input filter:   ACCEPT
     Output filter:  ACCEPT
     Routes:         13 imported, 2 exported, 13 preferred
     Route change stats:     received   rejected   filtered    ignored   
accepted
       [...]
     BGP Next hop:   x.x.x.x

Looking forward to get some clarifications.
Thank you.

Kind regards,
Davide Pucci.