Are Special Assessments part of SHST limits?

I understand that Special Assessments are normally considered Land Improvements and add to the land's basis and depreciated.

But what about when the Safe Harbor for Small Taxpayers (SHST) is elected?

Since the SHST only applies to the rental BUILDING, is it true that any special assessment tax paid is not part of the total expenses subject to the "2% of unadjusted basis" limit?

And the Assessment must be capitalized as not part of the SHST election?