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)