Meanwhile my Debian Testing systems have (per default) upgraded to libbsd 0.9.1 (and kernel 4.16.0-2). Unfortunaetly, this does not fix the problem (long ssdm start) under virtualization by kvm, although according to #898088 libvirt 0.9.0-1 should have alredy fixed this.
On productive bare metal I cannot say anything, as I have set kernel 4.16 on hold by apt. Thx, Chris