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)