Hi Adam,
Yes, the trial allows any resolution to be rendered. When you say it doesn’t allow larger images, do you mean the options are greyed-out, or is the problem something else, such as an error message, or your selection being ignored?
Were you able to successfully activate your trial using the 16-digit code that was emailed to you? Are any of the other Pro-only features available (e.g. artificial lights or global illumination)?
Regards,
Shaderlight support