You can only change order weight on the web app; this means you will pick and pack the order on the mobile app, then have to jump back to the web app to change the order weight and finish the order there, or jump back to the mobile app with the updated weight, and continue to despatch. It makes zero sense.
Agreed, the change order weight on mobile needs to exist. It doesn't make any sense to be able to pick, print a label, and dispatch an invoice, but not change the weight.