The estimates have absolutely nothing to do with bRAS profiles.
As b*cat said.. they are nothing more than best guesses.
About the only thing I can think may cause changes are perhaps your neighbours performance. Not that his line will affect yours, but more to do with that they can sometimes take the r/l speeds of any near/neighbouring lines as an indication to what you may perhaps be expected to get. For example if my neighbour got g.fast first and our line lengths are very similar, then the speed they sync at could be used to estimate what speed Openreach think I might be able to get.
TalkTalk Business doesn't have any bras ip profile?
You are thinking of LLU ADSL(2+) and their own MSANs in the exchange.
The streetcab DSLAMs belong to Openreach, so its Openreach's DLM.
I'm trying to think why you'd bring the ip-profile into it? ip-profile is based on your actual and real time sync speed.
With you mentioning PN are you thinking about the Plusnet line speed rate, which is based off the BTw ip-profile, but again nothing to do with DLM or speed estimates.