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)