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)