Allow attributes and segments to be excluded from Auto Personalisation and Auto Target models on a per-activity basis

Description - We need the ability to exclude specific data attributes / segments from Target's Auto Personalisation and Auto Target models on a per-activity basis. Currently it is possible to exclude attributes and segments at the client/account level, but this applies to all activities within the client/account.

Why is this feature important to you - In our AP activities we see some of the top influential attributes are, based on our intimate knowledge of the data, completely irrelevant to the activity or placement, and are leading to bias in the models. However, in other activities and placements the same attributes are highly relevant. We are not observing the level of performance from AP that we would expect, and attribute the biasing data attributes as one of the contributing factors. 

How would you like the feature to work - It would be ideal to control this in the UI ourselves, but if we have to go via Client Care that is fine.

Current Behaviour - It is not possible, the closest option is to exclude it from all AP & AT activities, which is not appropriate in many situations.