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)