Tore,
You should ask that IPRA should re-read 2015-03. If your customer is allocated a /29, the new allocation criteria currently proposed in 2015-03 can simply *not* be used to "resize" it to a /28. This is, as I've mentioned earlier, due to the fact that 2015-03 only changes the *initial* allocation criteria. If already allocated a /29, your customer would need to request a *subsequent* allocation in order to obtain a /28, but as the subsequent allocation criteria is not changed by 2015-03, it won't be of any help as far as your customer's concerned.
The 2015-03 proposal might still help/apply if you view the situation as being that the customer has not *outgrown* their /29 allocation (and hence needs consideration under the subsequent allocation policy) but rather that they have effectively *ordered the wrong size* in which case they could return the /29 and get a /28 in return under the new initial allocation criteria. If the /28 is able to encompass the first then this obviously carries the benefit of not requiring any renumbering. This is just speculation though and so, for clarity of understanding, it would be good to hear how RIPE NCC would see things operating in such a scenario... Mathew