Hello Iain,
The iLok system only allows one (standard-type) trial licence to be activated per product, so it isn't possible simply to obtain and activate a second trial for the same sample set, I'm afraid. However, if the maker of the sample set agrees to it, it is instead technically possible for MDA to deposit a special type of trial extension licence to you manually. Hence please contact the sample set producer to see whether they'd be prepared to do that, and ask them to contact MDA with the details via email to discuss it if so. Thanks.