Do we need "\forceglue"?
tanukihee do we need a command like "\forceglue", especially "\forcexkglue" or "\>" to tell luatexja to insert an xkanjiskip here and "\forcekglue" to tell luatexja to insert a kanjiskip there? And they will have the same priorities like other JAglues under luatexja-adjust.
That's a good idea. I'll work on the holiday season.
Note that \> is defined as a synonym of \medspace by LaTeX kernel (unlike \<), so I'm not sure that it is good to define \> always by the LuaTeX-ja package. (Personally, I prefer to define/use a short form \>.)
tanukihee What about "\+"? It is not defined by LaTeX neither. (But it's a quite important macro in TeX...)
tanukihee)
Added \insertxkanjiskip and \insertkanjiskip in commit 6be0fb5. By default, they use values at the execution place, but \insertxkanjiskip late and \insertkanjiskip late uses those at the end of the paragraph. I hope they work fine with luatexja-adjust.
shorthand form
I didn't put any shorthand form in LuaTeX-ja itself now.
I released LuaTeX-ja 20201224.0, which includes \insertxkanjiskip. But I leave this ticket open, because of the shorthand form.
Fork
In luatexja, we can use \inhibitglue or \< to stop luatexja inserting glue around a JAchar. But sometimes when we need to temporarily or forcibly insert a kanjiskip or an xkanjiskip (especially xkanjiskip), what can we do?
For example, I want to temporarily insert an xkanjiskip between ( and あ. In luatexja.dtx, (\hskip\ltjgetparameter{xkanjiskip}あ is used (line 2271), or we can use \ltjsetparameter{alxspmode...} to set it, but it cannot be multiply changed in one paragraph. However when luatexja-adjust is used, the JAglue will have priorities. The \hskip\ltjgetparameter{xkanjiskip} will be stretched firstly while other xkanjiskips are the third to be stretched.
Therefore, do we need a command like "\forceglue", especially "\forcexkglue" or "\>" to tell luatexja to insert an xkanjiskip here and "\forcekglue" to tell luatexja to insert a kanjiskip there? And they will have the same priorities like other JAglues under luatexja-adjust.
Just a discussion, thank you very much.