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)