Postal votes and PPC selections

(Reposted from Labourhome)

There is a growing controversy surrounding the use of postal votes in PPC selections: is this a new way to manipulate selections to ensure 'favourable' results?
The current party rules are quite clear. Party members are entitled to a postal vote for PPC selections, but under quite specific circumstances:
(c)Postal votes shall only be granted to those who are unable to attend a hustings meeting - not to those who choose not to attend. Postal votes will be granted for those who cannot attend due to a medical condition, cannot make reasonable travel arrangements, are away on holiday, have work commitments or caring responsibilities or any other appropriate reason for non-attendance at the hustings as agreed by the NEC designate representative. They will not be made available to those choosing to undertake other engagements unless they are candidates for selection in this process.
and
(e) No shortlisted nominee or any person acting on behalf of a nominee should benefit from interference in the process of applications for, or the issue and return of, postal votes. Any evidence of such interference may lead to the disqualification of the nominee concerned.
Are these rules being kept to?
The controversy is particularly stirring in Erith and Thamesmead (read this article in the Tribune for details). A third of the CLP apparently had 'appropriate reasons' for requiring a postal vote. Now, in Calder Valley, 90 people voted by post (nearly double the 50-odd who attended the meeting) inevitably having a massive impact on the result.
Now there is a perfectly legitimate argument in favour of ensuring as many people can participate in this process as possible, but if people want to pursue the route of an OMOV postal ballot, then it has to be structured, it has to be fair and equal, and the party would have to pay for CVs and statements from all candidates to go to all members, etc. That is one option. There is an equally legitimate argument to say that this decision should be taken primarily by people who have engaged in the process, have heard all the candidates and had the opportunity to challenge them face-to-face. Either way, what is happening in Erith and Thamesmead, and what appears to have happened in Calder Valley, is something different entirely.
Is uncertainty about this rule being used by external influences to influence the results of selections? Are people working on behalf of some nominees (or perhaps more clearly, working very clearly against some nominees) in order to ensure the decision is taken at a distance, that the arguments aren't heard, that the candidates aren't challenged? If that is the case then this is a very serious issue indeed.