Value 3 was chosen because there are some pertinent forms with three initial consonants attested already in the 18th century. Those with /t/ as second consonant all seem to be younger.
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007
Source: Wilner 2007