• Support is added via this PR feat(rum): allow creating blocking spans from agent api #875
• We didn't expose these options when creating blocking transactions and spans in our typings file for @elastic/apm-rum -

  apm-agent-rum-js/packages/rum/src/index.d.ts

  Line 151 in dc53188

  interface SpanOptions {

Details - https://discuss.elastic.co/t/is-it-possible-to-obtain-user-centric-metrics-with-custom-transactions/267707?u=felix_roessel