Hi Martin,
Greetings from Syncfusion.
We would like to let you know that we have restricted the size of leading and trailing view width to 24 pixels and overall margin is 12 as per the specification of material design.However, we have already logged a feature request for this requirement, and it can be tracked through our feedback portal below.
Please cast your vote to make it count. We will prioritize the features every release based on the demands and we do not have immediate plan to implement this feature since we committed with already planned work. So, this feature will be available any of our upcoming release. We appreciate your patience until then.
If you have any more specification/suggestions to the feature request, you can add it as a comment in the portal.
Regards,
Rachel.