Sounds good thanks.

It would be interesting to hear the reason the FRR chose this behavior as default for one of their profiles. It causes major reconvergence issues for BGP networks and I don't see an obvious benefit.

DFLT_BGP_IMPORT_CHECK can only be set by changing the profile? It can't be set directly? We don't need to change the default timers, just this parameter.

While you are working on this I'd suggest the default behavior to be to check if IGP routes exist by default. The reason most implementations check IGP is described in my initial bug submission along with diagrams. Since advertising unconditionally breaks dynamic routing it may make sense to make this a default.