I realized this was possible a while ago, and have been using it to great effect since that time, but neglected to share this with the community. So, here:
In short, shipstation allows you to enter in product weights up to 2 digit precision, and then make automation decisions based on that 2 digit precision of total order weight. If you carefully pick the weights of item classes, you can use this to create automation rules for multiple item orders (I have used certain prime numbers) as each total order weight will be unique. You can use this for anything that can be set with automation. There are some caveats:
To work with the single weight specified per line, I have been setting all rules to set a flag for a particular weight combo, and then afterwards using that flag to automate what I wish all such matching orders to do.
I have create a google sheet that details this and will allow you to easily copy and paste to create automation rules (unfortunately you have to use the GUI to set automation rules.)
Hope you enjoy!
Hey there @JakeM,
Thank you for providing this workflow you've worked on! The creative solutions and knowledge of the community continue to impress!
I'm sure that this type automation setup will be beneficial to many users now and down the road when they come across this post.