[Bibio]

use a virtual drive. these act as a dvd/bluray drive on your computer. when you click on an ISO it opens it up in the virtual drive so acts just like the disc would. kodi-dsplayer is then able to play it just like it would any disc that is not copy protected. if its supported in kodi-dsplayer as i'm under the impression that kodi-dsplayer wont open iso natively. but i could be wrong.

my advice would be to use makemkv and transfer all your iso to mkv (main title). unless that is you like to sit through the endless dribble of adverts, directors commentary, making of etc.etc. if you do then stick to iso.

i was the same as you at one point in that 90% of my stuff was ISO. trust me its well worth the effore to transfer to MKV. ISO and MKV are only ''containers'' for which the information is stored just like a zip or rar file.

Sorry, but this undesirable unless Kodi via a plugin or extension can auto mount when I select the ISO and then auto unmount upon completion or when closing the file. No conversions, either. Sorry. 

 take what you need from this thread https://forum.kodi.tv/showthread.php?tid=229692 or ask the brazen1 how its done. i personally dumped ISO as its tooo much trouble with compatibility.

from what i played with years ago regarding virtual drives, yes you can auto mount/unmount depending on how things are set up. a virtual drive is exactly the same as a a hardware drive as far as the computer and programs are concerned. it waits till its 'loaded' the ISO then 'ejects' it when done. clicking a file (movie) via kodi is exactly the same as without, its just that kodi creates a 'shortcut' to that file within its GUI. the OS/virtual drive should still 'see' the ISO being opened and place it in the virtual drive for playback. kodi might need a script written to tell it what to do regarding the file in the virtual drive.

best speak to brazen1 though.

is there any specific reason why you wont use MKV?