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)