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)