Thanks for the reply. I have used the /feedback command and got a few replies from Slack support.
I am also sharing my finding here as well.
- Slack snap has a 5 seconds delay on each start because the launch script calls
update-mime-databaseon each run. As shared via email, I have found that theelectron-launchscript in the Slack snap needs to add a line similar to this https://github.com/keshavbhatt/glate/blob/71096f2fe0506e1c0ae7fb46a4426321724b889a/snap_launcher/bin/desktop-launch#L581 - Using LZO compression for snap reduces 10 seconds on cold start. This was tested on Ryzen 3900X, 32GB RAM and 1TB Samsung 980 Pro SSD.
After emulating a fix for the first issue and recompressing the snap with LZO compression, I was able to get start up speeds similar to that of the deb package (give or take).
So I hope the development teams at Slack consider those findings and incorporate them into the package.