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)