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)