Greetings from Syncfusion.
Currently we do not have support to achieve your requirement “Support for polylines on SfMap“ but we have logged a feature request on this 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.
If you have any more specification/suggestions to the feature request, you can add it as a comment in the portal.