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)