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)