Noticed difference in sample rates in radio CDNs

[Timothy]

Hello,
With radio broadcasts, there seems to be some broadcasts with multiple servers. 
Using get_iplayer v2.9.1, I noticed that flashaacstd1-2 are 44.1 kHz, while 
flashaacstd3 is 48 kHz. I thought that the number suffixing the modes just 
indicates the various servers possible, and the content would be the same?

The sample rate for the flashaacstd modes aren't listed below, but I did 
partially download each stream individually and found that there is a sample 
rate difference. The bit rate is still the same across the three servers so I 
guess that's fine. I was just wondering if this is supposed to be the standard 
behavior for get_iplayer or not.

Interestingly enough, there's a working hlsaachigh stream available for nonlive 
broadcasts. I thought the release notes only indicated live TV and radio 
channels and not actual programs. I'm still good with a 320 kbps stream 
though...

I realize that this message is all over the place and poorly organized, but I'm 
just writing the words as I think them, without any attempts of organization.

PID: b0184v7x
flashaacstd1: (stream-uk-audio_streaming_aac_med) rtmp aac 128kbps stream (CDN: 
limelight/20)
flashaacstd2: (stream-uk-audio_streaming_aac_med) rtmp aac 128kbps stream (CDN: 
akamai/10)
flashaacstd3: (stream-uk-audio_streaming_aac_med_uk) rtmp aac 128kbps stream 
(CDN: limelight/9)
hlsaachigh1: (hls_iplayer_317) hls aac 317kbps stream (CDN: akamai_hls_open/10)

Timothy