If you lay off partially you can sign up for your state's Work Share program which means no increase in your UI tax rate.
Each state has its own rules but any state that offered a Work Share program prior to March 27, 2020 (CARES Act passage date) gets 100% funding for Work Share, while states who are only implementing a program now receive 50% funding which means employers in those states will only have 50% of UI costs billed to their account.
Link to detailed post on this in my signature line.