How to make a table with multirow rotated cells?

I am trying to make the table with automatically centered, rotated multirow cells. Something like in the picture, but with cells automatically fitted to their content:

I tried to apply solutions given by @AboAmmar and @Seong, but these not ensure vertical centering within the specified number of rows. This answer is unclear, because multirow command under makecell package accepts non-integer value of number of rows (?). Here is given some code, but the problem is that this engages fixed value (in raisebox argument) which is proper only for one specific cell content. The most similar question is without answer.

In fact I need some function which should be named multirowrothead – as a combination of multirowthead and rothead functions of the makecell package.
My code:

documentclass[table]{standalone}
usepackage{siunitx}
usepackage{makecell}
usepackage{xcolor}
usepackage{multirow}
usepackage{hhline}
renewcommand{theadfont}{normalsizebfseries}
renewcommand{arraystretch}{1.3}

begin{document}
    begin{tabular}{
        |l|
        S[table-format=2.1]|
        S[table-format=1.2]|
        S[table-format=2.1]|
        S[table-format=1.2]|
        S[table-format=2.1]|
        S[table-format=1.2]|
    }
        hline
        % https://tex.stackexchange.com/questions/246889/how-to-color-column-heads-determined-width-makecell
        rowcolor{gray}
        multicolumn{3}{|c|}{colorbox{gray}{thead{First title in heading}}} &
        multicolumn{2}{c|}{colorbox{gray}{thead{Second titlein heading}}} & &
        hhline{>{arrayrulecolor{black}}|-----|>{arrayrulecolor{gray}}-%
            >{arrayrulecolor{black}}|>{arrayrulecolor{gray}}->{arrayrulecolor{black}}|%
        }
        rowcolor{gray}
        & & & & colorbox{gray}{thead{datadescription}} &
        {multirowthead{-2}{Datadescription}} &
        hhline{%
            >{arrayrulecolor{black}}|>{arrayrulecolor{gray}}-%
            >{arrayrulecolor{black}}|>{arrayrulecolor{gray}}-%
            >{arrayrulecolor{black}}|>{arrayrulecolor{gray}}-%
            >{arrayrulecolor{black}}|>{arrayrulecolor{gray}}-%
            >{arrayrulecolor{black}}|-|-|%
            >{arrayrulecolor{gray}}->{arrayrulecolor{black}}|%
        }
        rowcolor{gray}
        colorbox{gray}{multirowthead{-2}{side-headingdescription}} &
        colorbox{gray}{multirowthead{-2}{datadescription}} &
        colorbox{gray}{multirowthead{-2}{datadescription}} &
        colorbox{gray}{multirowthead{-2}{datadescription}} &
        colorbox{gray}{thead{A}} & colorbox{gray}{thead{B}} &
        colorbox{gray}{multirowthead{-3}{Data description}}
        hline
        Description 1 & 63.5 & 4.87 & 63.5 & 4.87 & 63.5 & 4.87
        hline
        Description 2 & 88.4 & 5.13 & 88.4 & 5.13 & 88.4 & 5.13
        hline
    end{tabular}
end{document}

documentclass[table]{article}
usepackage{siunitx}
usepackage{makecell}
renewcommand{arraystretch}{1.3}

usepackage{nicematrix}

begin{document}
begin{NiceTabular}[ hvlines , code-before = rowcolor{gray!30}{1-3} ]   
    {
        c
        S[table-format=2.1]
        S[table-format=1.2]
        S[table-format=2.1]
        S[table-format=1.2]
        S[table-format=2.1]
        S[table-format=1.2]
    }%
{Block{1-3}{First title in heading}} & & & 
  multicolumn{2}{c}{makecell{Second titlein heading}} & 
{Block{2-1}<rotate>{Datadescription}} &  
{Block{3-1}<rotate>{Data description}} 
  {Block{2-1}<rotate>{side-headingdescription}}
& {Block{2-1}<rotate>{datadescription}}
& {Block{2-1}<rotate>{datadescription}}
& {Block{2-1}<rotate>{datadescription}}
& rotate makecell{datadescription}hspace*{0.5em} 
& & & & {A} & {B} 
Description 1 & 63.5 & 4.87 & 63.5 & 4.87 & 63.5 & 4.87
Description 2 & 88.4 & 5.13 & 88.4 & 5.13 & 88.4 & 5.13
end{NiceTabular}
end{document}