Obviously there are lots of senior CD's. Here's the list from ice-dance.com
http://www.ice-dance.com/reference/83-compulsory-dance-descriptions-a-patterns
One iteration takes:
Argentine Tango 35 seconds
Austrian waltz 49 seconds
Blues 24.7 seconds
Finnstep 38 seconds
Killian 8.3 seconds
Midnight Blues 49 seconds
Paso Doble 17 seconds
Quickstep 15 seconds
Ravensburger Waltz 29 seconds
Starlight Waltz 35 seconds
Tango Romantica 52.5 seconds
Viennese waltz 23 seconds
Westminster waltz 29 seconds
Yankee polka 32 seconds
So if the polka is OK with 32 seconds, I would think that everything other than the Finnstep, Tango Romantica, Midnight Blues & Austrian Waltz could be fitted in, one way or another. Since the key points are a mashup of several steps oftentimes, there has to be a relatively simple way to do this for many of those CD's.
And if the quickstep is OK, you'd think the paso doble would be OK.
So I clearly don't understand why only the Quickstep or polka would do, and hope someone will explain it to me.
I'd love to see one iteration of the Finnstep rather than the Quickstep, for example.
And in fact, the ChaCha Congalado worked really well for the juniors, and is no harder than the Quickstep which has been done as a junior dance. Also the Viennese worked well for the juniors last year, and is at least as interesting as the quickstep.