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)