Fonts

<..amsfonts.4ht..>
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % amsfonts.4ht                          2014-07-12-22:36 %
 % Copyright (C) 2001--2009       Eitan M. Gurari         %
 <.TeX4ht copyright.>
   <.amsfonts sty.>
 \Hinput{amsfonts}
 \endinput
 -_-_-

<..amsfonts sty..>
 \NewConfigure{mathbb}{2}
 \def\:temp#1{{\a:mathbb \o:@mathbb:{#1}\b:mathbb}}
 \HLet\@mathbb\:temp
 -_-_-

<..amsfonts sty..>+
 \NewConfigure{mathfrak}{2}
 \def\:temp#1{{\a:mathfrak \o:@mathfrak:{#1}\b:mathfrak}}
 \HLet\@mathfrak\:temp
 -_-_-

Commands like \rm need low level implemetation through dynamic configurations of symbols decorations at the htf source (e.g., ${\textbf abc}XX\bf abc \mathbf ab\mathbb{C}d\mathsf{C}$).

amstext.sty

<..amstext.4ht..>
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % amstext.4ht                           2014-07-12-22:36 %
 % Copyright (C) 2000--2009       Eitan M. Gurari         %
 <.TeX4ht copyright.>
 
 \def\:tempc#1{\hbox{\a:text#1\b:text}}
 \HLet\text@=\:tempc
 \NewConfigure{text}{2}
 
 \Hinput{amstext}
 \endinput
 -_-_-