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)