Gdtyjr

This is a follow-up of a previous question I asked before.

I am using newpxtext and eulerpx packages, and I want to change the typesetting of operator names to use sans serif type. I implemented egreg's answer:

documentclassamsart
usepackage[utf8]inputenc
usepackage[T1]fontenc
usepackagemathtools,newpxtext,eulerpx

% a new symbol font for names of operators
DeclareSymbolFontsfoperatorsOT1cmssmn
% don't waste a math group
DeclareSymbolFontAlphabetmathsfsfoperators
% tell LaTeX to use sfoperators for names of operators
makeatletter
renewcommandoperator@fontmathgroupsymsfoperators
makeatother

This works for already defined operator names (max,sin,etc.) and also for custom-defined operatornames (via DeclareMathOperator). The problem arises when I try to define a operatorname involving accents: concretely, I want to define the operatorname "máx" (which stands for "máximo", which means "maximum" in Portuguese). The following code

DeclareMathOperatorgraugrau
DeclareMathOperatormAxmáx

begindocument
$degquadgrauquadmaxquadmAx$
enddocument

has output

which, besides the fact that the accented "a" is not appearing in sans serif type, generates the warning

'Command ' invalid in math mode on input line ** ',

which is expected, because we must work in math mode instead of text mode. If I use

DeclareMathOperatormAxmacuteax

instead, the output has the same problem as in my previous question:

Trying to implement Davislor's solution

DeclareMathOperatormAxmacutemathsf ax

does not work, either: it has exactly the same output as before.

Finally, here is a brute-force alternative that works:

DeclareMathOperatormAxmmbox$acutemathsf a$x

(Obviously, I don't want to resort to this ugly method). Is there some way to solve this issue?