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)