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)