underministic privileged identity management deployments

Bicep version
Bicep CLI version 0.25.53 (c0ad57dff6)

Describe the bug
We're trying to incorporate privileged identity management in deployment of subscriptions to our product teams. We want to deploy the ability for developers to activate contributor permissions at the subscription level. Changes to our access structure would mean redeployment of templates. They need to be idempotent for this to work properly (as most azure resources already are).
As of now, consecutive deployments of privileged identity management assignments fails with conflict after the initial deploy.

To Reproduce
deploy the bicep file twice on subscription level with az bicep deployment sub create

var contributor_role = resourceId('Microsoft.Authorization/roleDefinitions', 'b24988ac-6180-42a0-ab88-20f7382dd24c')

@description('object id of principal that should have eligibility for contributor permissions')
param ownerId string = '[REDACTED]'


param startTime string = utcNow()

resource owner_contributor_ligibility 'Microsoft.Authorization/roleEligibilityScheduleRequests@2022-04-01-preview' = {
  name: guid(contributor_role, ownerId) // note that this does not change between deployments
  properties: {
    principalId: ownerId
    requestType: 'AdminUpdate'
    roleDefinitionId: contributor_role
    scheduleInfo: {
      expiration: {
        duration: 'P365D'
        type: 'AfterDuration'
      }
      startDateTime: startTime
    }
  }
}

Additional context
consecutive deployments yield the following error:

{
  "code": "Conflict",
  "message": "A role assignment request with Id: 7aede46e-bf0f-5b59-966c-48ccd70209b2 already exists",
  "target": "/subscriptions/[REDACTED]/providers/Microsoft.Authorization/roleEligibilityScheduleRequests/7aede46e-bf0f-5b59-966c-48ccd70209b2"
}

Start with the provided Bicep resource and reproduce the issue by running the subscription deployment twice with az bicep deployment sub create. Investigate the Microsoft.Authorization/roleEligibilityScheduleRequests@2022-04-01-preview behavior for repeated AdminUpdate requests with the same name and confirm what idempotent behavior should look like.