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)