[tex4ht] How to increase number of strings ? make4ht-lib: Fatal error. Command htlatex returned exit code 1

[Nasser M. Abbasi]

I am getting lost sections in the table of content for
the very last chapter in the HTML.

It shows only the first 2 sections in the last chapter. But
there are 9 sections there.  It only happens when the document is large.

It seems to be related to some limit buildin.

So I made a MWE to try to find out why. Now on the MWE I get
this error

-----------------------------------------
[27910]
l.36 --- TeX4ht warning --- \Link{ }? ---
! TeX capacity exceeded, sorry [number of strings=477757].
\:aplus ...dafter \noexpand \:temp {\the \tmp:cnt
                                                    }}\egroup \:temp
l.36 }

   1508 words of node memory still in use:
     17 hlist, 2 vlist, 2 rule, 1 disc, 4 local_par, 1 dir, 22 glue, 5 kern, 4 pe
nalty, 30 glyph, 33 attribute, 116 glue_spec, 33 attribute_list, 1 temp, 4 if_s
tack, 4 write, 26 special nodes
     avail lists: 1:1,2:502,3:885,4:5,5:25,6:67,7:1336,9:158,10:4,11:3
!  ==> Fatal error occurred, bad output DVI file produced!
Output written on foo.dvi (27910 pages, 173384940 bytes).
--------------------

I searched and do not see where to increase number of strings.

My current .cnf is

>cat /usr/local/texlive/2022/texmf.cnf
buf_size=90000000
pool_size=90000000
main_memory=80000000
save_size=1000000


How does one increase "number of strings"?  I have 128 GB of ram.

On a related possible issue: does tex4ht uses lualatex in any way?
I know it uses dvilualatex. does dvilualatex uses lualatex?

Here is the MWE and the command I used.

=======================
\documentclass[12pt]{book}
\usepackage{pgffor}

\begin{document}
\ifdefined\HCode
\Configure{tableofcontents*}{chapter,section}
\else
\setcounter{tocdepth}{1}
\tableofcontents
\fi

\ifdefined\HCode
\TocAt{chapter,section}
\TocAt{section,subsection}
\fi

\foreach \n in {1,...,50}%
{
    \chapter{\n}
    \foreach \m in {1,...,10}%
    {
        \section{\m}
        \foreach \k in {1,...,200}%
        {
           \subsection{\k}
        }
    }
}
\end{document}
====================================

>make4ht  -ulm default foo.tex "mathjax,htm,fn-in,4"
[STATUS]  make4ht: Conversion started
[STATUS]  make4ht: Input file: foo.tex
[ERROR]   htlatex: Compilation errors in the htlatex run
[ERROR]   htlatex: Filename     Line    Message
[ERROR]   htlatex: ?    36       TeX capacity exceeded, sorry [number of strings=477757].
[ERROR]   htlatex: ?    36        ==> Fatal error occurred, bad output DVI file produced!
[FATAL]   make4ht-lib: Fatal error. Command htlatex returned exit code 1
>


Thanks
--Nasser