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)