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)