Beamer metropolis theme, recommend a math font that matches with Fira

Update

I have just discovered the existence of FiraMath font, here an example of the font from https://github.com/firamath/firamath

The Github repository above gives instructions for installing the font ­– but it's already in Texlive – and instructions to use it in XeLaTeX or LuaLaTeX that I report for completeness

\documentclass{article}
\usepackage{amsmath}
\usepackage[mathrm=sym]{unicode-math}
\setmathfont{Fira Math}

\begin{document}
\[
  \int_0^{\mathrm{\pi}} \sin x \, \mathrm{d}x = 2
\]
\end{document}

---

I've found that arevmath is the way to go, but to have a good match with the metropolis theme one has to modify slightly the weights of Fira. metropolis uses Fira Lightand Fira Book for regular and bold text, that are both light when compared to arev mathematical characters. To have a better match I've changed in the preamble the sans font and the relevant variations as follows

\documentclass[aspectratio=169]{beamer}
\usetheme{metropolis}
\usepackage{arevmath}
\setsansfont[
  BoldFont={Fira Sans SemiBold},
  ItalicFont={Fira Sans BookItalic},
  BoldItalicFont={Fira Sans SemiBold Italic}
]{Fira Sans Book}
\begin{document}
% ...

and using the following body

% ...
\emph{ABCDEFG abcdefg 0123456789}\\
\textbf{ABCDEFG abcdefg 0123456789}\\
\emph{\textbf{ABCDEFG abcdefg 0123456789}}
\[z = f(g)-B-\kappa x+\beta n = (1-\kappa\xi).\]
\[z = \boldsymbol{f}(g)-B-\kappa x+\beta n = (1-\boldsymbol{\kappa}\xi).\]
\end{document}

I can have the following results

In my opinion there is a good match between math and text but I'm very open to criticisms.

Perhaps eulervm, though it is obviously a question of preference. In this case, I find the weight, the taper, and ornamentation (i.e., curliness) to be a better fit.

\documentclass[aspectratio=169]{beamer}
\usepackage{eulervm}
\usetheme[titleformat=smallcaps,block=fill]{metropolis}
%\metroset{outer/frametitleformat=smallcaps}
\setbeamertemplate{navigation symbols}{}
\setbeamertemplate{blocks}[rounded]
\begin{document}
\begin{frame}
$z = d - \kappa x = (1 - \kappa\xi) d = \zeta d$
\end{frame}
\end{document}

For comparison, with standard math font:

POSTSCRIPT

My example was compiled in pdflatex. Interestingly, the OP points out (and I can confirm) that running either of my two examples in xelatex or lualatex inexplicably increases the size of the text font. Very strange.