I know I'm not alone in my dislike for the new "hamburger menu" feature. It has resulted in quite a bit of retraining at our facility, across all 3 shifts, sucking time from my already packed day. The additional clicks necessary to access "active" sheets for the day is almost exhausting.
While I certainly hope Smartsheet LISTENS to our complaints, and returns to the prior interface, I have found a partial work around that has worked OK for me today.
While in the "hamburger menu", click on the file you want to open then right click and select "Open in New Tab". Repeat this for the tabs you are actively using that day / week. Now all of them are visible like they where in the old interface. If you will continue to work in these tabs, set your default launch pages in your browser to open "current pages". The next time you launch your browser, the same tabs will be visible.
Again - this is NOT a long term fix. We should NOT have to continue to adjust our workflow to accommodate a change which added no value to the end user. We need to continue to work smarter NOT harder.