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)