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)