Is showing E-Mail Inline Attachments in Exchange/Outlook a bad practice?

Question 1

We are currently in the situation that we receive some E-Mails from our business partners containing inline attachments of the file types .doc(x) and .pdf with our Exchange Server.

Outlook does not show those files by default. I know there is a Exchange setting that tells Outlook to display inline attachments.
For those curious, it is Set-OrganizationConfig -ShowInlineAttachments:$true.

Before I apply that setting, I am curious to know whether I should even consider it. I do not want to implement a bad practice and I have the feeling that there is a reason this is $false by default. I rather educate our business partner.

Edit

For clarification: Inline attachments ≠ automatic attachment preview.

In the following picture you see the difference between inline attachments and regular attachments. The first is disabled for Outlook clients in a domain environment by before stated Exchange setting.

(Source: http://blogs.mccombs.utexas.edu/the-most/2011/01/28/email-attachments-in-the-body-of-outlook-messages/)

Question 2

Is showing E-Mail Inline Attachments in Exchange/Outlook a bad practice?

Most pertinent is that automatically rendering inline attachments is a theoretical attack vector, which has been exploited, and remains possible to, insofar as a zero-day remains to be discovered within Outlook. However, this is rare, and the potential convenience improvement is significant.

Unfortunately, for advanced image and document formats, the previewer may not support a sufficiently advanced rendering environment for the document to appear as it should. This is especially true if macros are embedded. In that case, forcing files to render in dedicated viewers may prevent confusion amongst recipients.

Otherwise, the size should be identical, for whether the Content-Disposition is inline or attachment, the file's encodement is data:.*;base64 regardless.

However, some files must render inline. These include signatures' images.