Jim Sanborn Has release 4 hints to the text of Kryptos over the years:

• BERLIN on november 17th 2010 
• CLOCK on november 9th 2014 [Berlin wall 25th anniversary]
• NORTHEAST on January 29th 2020
• EAST  April 2020

Sanborn has said:

The fall of the Berlin wall influenced the encryption development 

"you'd better delve into that particular clock" then added "there are several really interesting clocks in Berlin"

April 2006 Sanborn stated that he omitted a letter from the encrypted side "for aesthetic reasons, to keep the sculpture visually balanced"

Ed Scheidt has said:

He indicated that the codes were designed to be solved in five, seven or ten years.