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)