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)