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)