In evenmore pp. 76-77, concerning LMTX extended macro parsing, the following examples of #0, #+ and #- are given

\def\TestA#1#2#3{{(#1)(#2)(#3)}}
\def\TestB#1#0#3{(#1)(#2)(#3)}
\def\TestC#1#+#3{(#1)(#2)(#3)}
\def\TestD#1#-#2{(#1)(#2)}

\TestA1{\red 2}3
\TestB1{\red 2}3
\TestC1{\red 2}3
\TestD1{\red 2}3

give

(1)(2)(3) % red from "2" onward

(1)()(3)

(1)(2)(3) % only "2" is colored

(1)(3)

What I guess is that #+ pass an argument, grouping braces included (the report says an argument is passed "as-is"). I see it as really useful. But, apart from the example above, are there any other differences between doing, say, \def\foo#1#2#3 and \def\foo#+#+#+{#1#2#3}? Thank you very much.

Cordially,

Jairo :)