Currently it is not possible to filter records or specify fields when using {{suitecrm.url}}/Api/V8/module/{moduleName}/{id}/relationships/{linkFieldName}
this leads to overfetching which could be avoided by honouring the filter and fields parameters used by {{suitecrm.url}}/Api/V8/module/{moduleName}/{id}
or {{suitecrm.url}}/Api/V8/module/{moduleName}
I have an incentive to make this change to reduce the amount of requests made to the V8 API, and so I will most likely solve this myself and share