route-map based on next-hop

General questions
1

Ok, i’m trying to figure out how to set some blackholing routes.
I have to do this differently based on my upstream carrier.

So, step 1: how can I create a route-map matching all IPs with a defined next-hop?
I’ve tried like this:

set protocols static route 2.3.4.5 blackhole
set protocols static route 1.2.3.4 next-hop 2.3.4.5

but this isn’t matched by a route-map:

set policy prefix-list PL-TEST rule 1 prefix 2.3.4.5 
set policy route-map TEST rule 1 match ip nexthop prefix-list PL-TEST

(i’ve removed the action policy when posting in the forum, both prefix-list and route-map are created properly)