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)