JCB began publishing Review Comments (AKA Review Process File, RPF, Review History) in August of 2018.  JGP added the workflow in October 2022. Below is an overview of the process:

EJP

Authors are asked the following at submission:

Review Process File in case of Acceptance

Authors have the option to publish an online supplementary document with all formal correspondence between authors and editors for accepted manuscripts that were directly submitted to <journal name>. Referee anonymity will be maintained. Authors may request that data specifically included in the response to referees and intended for publication elsewhere be redacted from the document. It is the author's responsibility to notify the editorial office should such redaction be needed. Authors can modify this choice at any time prior to editorial acceptance.
_Yes, publish all formal correspondence
_No, do not publish all formal correspondence

If Yes is selected, the PDF will be automatically generated when the article is accepted. There will also be a link in EJP to manually generate the file when the manuscript hits the Post Decision-Acceptance folder or the Export System folder.

There is also a row on the details page indicating  the answer:

RPF: Yes: publish all formal correspondence

The Reviewer Invite letter includes the following:

In addition, for accepted manuscripts, authors have the option to publish online all editorial correspondence alongside their article. This includes reviewer comments to the authors. Confidential reviewer comments to the Editor will not be published, nor will reviewer identities unless explicitly requested by the reviewer.

Public Website 

Here’s what JCB has on their about page (https://rupress.org/jcb/pages/about#process):

When manuscripts submitted to JCB are accepted for publication, authors have the option to publish the editorial correspondence and reviewer reports. Referee anonymity will be maintained. Manuscripts transferred to JCB along with reviewer reports from another journal are not eligible for this feature.

And on https://rupress.org/jcb/pages/editorial-policies#revcomments:

Peer review correspondence

Authors have the option to publish all formal correspondence for their accepted manuscript. This peer review correspondence will be published as a supplementary file online, including all editorial decision letters, peer reviewer comments to the authors, and author responses. Authors can modify this choice at any time prior to editorial acceptance. Authors also may request that data specifically included in the response to reviewers and intended for publication elsewhere be redacted from the document. It is the authors' responsibility to notify the editorial office should such redaction be needed. Reviewer comments originally submitted to another journal and transferred to Journal of Cell Biology will not be published online.

JPS

As long as the file exists, it will be exported to JPS and tagging will be included in the eXtyles metadata file and the file will be downloaded with other manuscript files. When the metadata is imported to eXtyles, the correct tagging will be added in the background. When exported, the following will be included in the JATS XML:

<self-uri content-type='reviewer_comments' xlink:href='JCB_201812345_review_history.pdf'/>

The JCB_XXX_review_history.pdf file travels through the workflow, but it does not appear in all of the tabs in JPS.

RPFs will be published online only, and will appear as a separate tab in the article display, as you can see on LSA. E.g. http://www.life-science-alliance.org/content/1/4/e201800079

Late files

In cases where editorial sends the RPF to production after the manuscript, the file needs to be added as a new file:

Object Type: Review History
Format Type: Review History
Status: Send to Vendor

Depending on the timing, different additional actions need to be taken:

• If it's not too late to update the eXtyles metadata, then simply generate a new file after uploading the RPF.

• If that ship has sailed, and you already have XML that is in ProofCentral, then you need to add a link to the article XML: 
  <self-uri content-type='reviewer_comments' xlink:href='JCB_202012345_review_history.pdf'/><label>Review History</label> needs to be added directly above the <history> element. 

            <supplementary-material content-type="featured-figure" id="featfig">

                <graphic xlink:href="JCB_201908036_thumb.gif"/>

            </supplementary-material>

            <supplementary-material content-type="peer-review"

                xlink:href="JCB_201908036_review_history.pdf">

                <label>Review History</label>

            </supplementary-material>

            <history>

                <date date-type="received" iso-8601-date="2019-08-03">

                    <day>03</day>

                    <month>August</month>

                    <year>2019</year>