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)