Mass email with variable in subject

I am trying to send a mass email on eMclient for macOS, and don’t want the replies from everyone to be in the same thread.

So, I’m trying to put a variable in the subject line.

I used {Prefix[fallback]} in both the subject and message body of a test email.

I get the contents of Prefix in the message body, but the subject line used fallback

I see in Still missing or bugs that I have noticed - #9 by Nage that I’m not the only one to see this issue.

Is there a fix on the timeline, or maybe an older version I could download where this worked?

I was using version 10.1.4828 for macOS, and thought I was up to date because the check for updates said no new version was available.

I’ve just installed 10.3.1524 (2e684e9) and this appears to be fixed.

So maybe the issue was fixed?

I did seem to have an issue with more than one variable in the subject, but I only tried that because I was testing things out