Problem: pre-estimation don't run in parallel

[yihuang]

Closes: #XXX

Description

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For contributor use:

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

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For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 53 lines in your changes missing coverage. Please review.

Project coverage is 60.11%. Comparing base (79bb39e) to head (6629d4e).
Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
app/executor.go	0.00%	53 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #523      +/-   ##
===========================================
- Coverage    60.24%   60.11%   -0.13%     
===========================================
  Files          128      128              
  Lines         9800     9821      +21     
===========================================
  Hits          5904     5904              
- Misses        3315     3336      +21     
  Partials       581      581              

Files with missing lines	Coverage Δ
app/executor.go	3.12% <0.00%> (-0.62%)	⬇️