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)