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)