upsides to making a portal to heaven  
    to  build   the   factory  there    
  
                                          
 first  of  all, real  estate: the highly 
 fractalized  geometry  (not  proven  but 
 likely  to  be the case) implies  almost 
 unlimited room;  even if the portal tech 
 would  be  stolen,  chances  of  running 
 into  a competitor  is  close  to  none, 
                                          
 secondly,  the  resources:  heavens  own 
 alchemical   properties  (proof  exist!) 
 makes  most  base  materials  easily and 
 readily  available.  once the  molecular 
 movement patterns  are  mapped  out, any 
 compound   can   be  created   virtually 
 without                            cost. 
                                          
                                          
  
   downsides to  making  a  portal  to  
  heaven to  build  the  factory there  
  
                                          
 current  portal  tech takes some  energy 
 to  hold open, which  isn't a problem in 
 itself. test  results however has  shown 
 that  without an active tether, heaven's 
 time  flow breaks down completely.  even 
 a  momentary  fluctuation  of the portal 
 would   render   all    remote    assets 
 practically  lost.  much  care  must  be 
 taken  to   maintain  portal  stability. 
 (one option  could be  several  portals)