Character separator for salted hashes
With most salted hash types that are available in hashcat, I see that a single dot is used as a character separator for the password and salt.

One example is:
 120 | sha1($salt.$pass)                                | Raw Hash, Salted and/or Iterated

With hash type 120 as an example, could hash type 100 be used in combination with a mode 7 hybrid attack, assuming that the salt value was short enough to make a mask attack practical?
  7 | Hybrid Mask + Wordlist

Also, is there an actual dot as part of most salted values or is that just extra syntax to denote a separate password and salt?

In other words, again, using hash type 120 as an example, do I need to concern myself with an actual dot character being part of the SHA1 encrypted value?

Which one of these gets encrypted with hash type 120?  Does it happen with a dot or without a dot?

The dot represents concatenation. If there was a literal dot we'd write e.g. sha1($salt.'.'.$pass)

You can simulate sha1($salt.$pass) by running sha1($pass) with -a 7, sure. But this is not a good idea with multiple salts because then you will not eliminate any salts once all hashes with that salt have been cracked. In other words, Hashcat is smarter than you Wink