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)