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)