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)