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)