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)