I have modifiers on the number row of my laptop’s keyboard, e.g.,

 key <AE07> {
     type= "FOUR_LEVEL",
     symbols[Group1]= [     Mode_switch,       ampersand,        NoSymbol,        NoSymbol ]
 };
 key <AE08> {
     type= "FOUR_LEVEL",
     symbols[Group1]= [          Meta_R,        asterisk,        NoSymbol,        NoSymbol ]
 };

and so on.

However, Shift+7, Shift+8 (etc.) have stopped working as desired in the
most recent Emacs build, although these bindings still work fine in
alacritty, Firefox, and other X Windows programs.  (In particular, the
binding works as desired in emacs -nw running under Alacritty.)

I’ve attached my full set of bindings here.  You should be able try them
out on a temporary basis via

xkbcomp $DISPLAY xkb.dump
xkbcomp ~/mbp.xkb $DISPLAY > /dev/null 2>&1
xkbcomp ~/xkb.dump $DISPLAY > /dev/null 2>&1

TL;DR: With mbp.xkb bindings in effect, Shift+7 will produce an "&" in
your terminal, but it doesn’t do this on the X Windows version of Emacs.