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)