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)