Annoying lag while typing into composer

If you have Keyboard Maestro and want to try yourself:

https://forum.keyboardmaestro.com/t/how-to-paste-text-but-slow-down...

I have started experiencing this issue today after updating macOS 10.14.5 to 10.14.6. I am running MailMate 5673.

I think I have found a link between the lag and Markdown, which may help narrow the issue down. Here is what I have noticed:

• If I compose a new blank message, regardless of the composer being set to Markdown or plain text, and regardless of the message preview being on or off, then I experience lag when typing "naturally";
• If I switch the composer to Markdown mode, then the lag is present until I type some valid Markdown syntax, after which the lag disappears. (Again, this seems to apply regardless of the message preview being on or off);
• If I switch the composer to plain text mode, and write some text including some Markdown syntax, the lag is still there.

So, in short, when the composer is in Markdown mode, and some valid Markdown is present in the message body, the lag disappears.

And a workaround is to have Markdown set as the default for composer, and have a signature with some Markdown syntax in it :-)

The "lag" seems to occur during momentary pauses in typing, as if a "preview update" is taking place. If I just bash random keys very quickly, then I can type a lot of characters without any lag. As soon as I introduce a tiny pause (which seems to occur naturally when typing), the lag shows up. I guess that the pause is somehow detected and triggers some kind of parsing to take place.

Also, I've tried turning off inline styling, code highlighting, spell check, none of which appear to make any difference.

I guess this may well be related to tickets #2408 and #2435, but I didn't really want to cross-post or start a new ticket.

It's a known issue although it's still unknown why it's much worse for some users than for others. It's new to me that it occurs when Markdown is not used. I'll keep that in mind.

That said, I recently made some changes which allows the preview to work better asynchronously. To try it out: Hold down the option key while clicking “Check Now” in the Software Update preferences pane.

@Louis: Sorry about the late reply and thanks for the video.

As a long time Mailmate user I haven't experienced this before at all. Just few weeks ago I did clean install of MailMate on M1 MacBook Air and the lag is very bad since the first launch.

Edit: I don't use Markdown rendering.

I am also experiencing some quite intrusive lagging when using the composer on an M1 Air (11.5.2/1.13.2). Like Will, I'm "getting around it" by inserting some dummy markdown syntax (like a bold) at the head of the message, removing most of the lag. The issue is not present on my older Intel MacBook Pro running the same versions.

EDIT: This seems to have already been fixed in 5818, missed that it was a thing. Sorry for the ticket necro!