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)