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)