In example below, style font=\Huge is set for cell (2,3) in a 3x2 tblr tabular. It should have no effect because (2,3) is out of bound. But now the style is applied to a wrong cell (3,1).
\documentclass{article}
\usepackage{tabularray}
\SetTblrInner{
cells={preto={(\therownum, \thecolnum)}},
hline{1,Z},
vline{1,Z},
}
\begin{document}
\begin{tblr}{cell{2}{3}={font=\Huge}}
& \\ \\ \\
\end{tblr}
\end{document}

My findings so far
Additional checks for overflow row or col numbers is needed, perhaps in \__tblr_data_item:nnnn and \__tblr_data_gput:nnnnn, where row and col numbers are available and not combined into a single index of some intarray.
Currently there's only an intarray-beyond-bound check in \__tblr_intarray_gset:Nnn. But if a cell is indeed out-of-bound but its index in intarray is not, corresponding style settings for this cell is not ignored.
In example below, style
font=\Hugeis set for cell (2,3) in a 3x2 tblr tabular. It should have no effect because (2,3) is out of bound. But now the style is applied to a wrong cell (3,1).My findings so far
Additional checks for overflow row or col numbers is needed, perhaps in
\__tblr_data_item:nnnnand\__tblr_data_gput:nnnnn, where row and col numbers are available and not combined into a single index of some intarray.Currently there's only an
intarray-beyond-boundcheck in\__tblr_intarray_gset:Nnn. But if a cell is indeed out-of-bound but its index in intarray is not, corresponding style settings for this cell is not ignored.