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)