Serious lag when activating save window with 12 tabs

Steps:

1. Compact tab
2. Switch saved windows in place (I doubt this affect result, but this is for easier recording and also my daily usage)
   
3. Create a saved window with 12 pin tabs
   

Maybe one of following:

1. Reversed the change back to previous behavior: pin tab suspend on window start
2. Implement #10755 asap

Version 0.99.132.2-rc (WebKit 621.1.2.111.4)

Sequoia (15)