1.An LR "Keyword Set" displays only 1-9 KWs you have to pick individually.
  2.KW panel box works but is totally manual needing multiple settings.
  3.Metadata Sync works but needs careful selection and multiple KW settings.
  4.KB shortcutting suffers the same, needing much manual configuring.
  5.Spray Can is the fastest but also needs manual KW entry.

1. Locate (or create) the desired Keyword Set in this text file.
2. Highlight and copy the keywords for that set.
3. Enable the "Paint Can" tool at the bottom of the LR gallery view.
4. Select [Keywords] as the type of the Paint action
5. Paste your copied keywords from this file into the Paint data box.
   Nb. I've successfully loaded 520+ characters into that data box.
6. Then Paint the images you want to add those keywords to.

--- GSM W2015 Issue
Typ>Fashion, Typ>Glamour, Place>Bahamas>Nassau>OldPort,
Client>GSM, People>GizelleP, Season>Winter, Fmt>Pal>Color, Age>30-40

--- PoulinG Wedding 2014-12-31
Loc>Can>Que>Mtl>Carre-St-Louis, Client>GrenierJP, Season>Winter, Fmt>Pal>Color