1. Definitely very useful, e.g. you do not really have to run an external viewer.
2. Installation here:
a. you must add 'Image' to the autoload list (menu > 'Macro' > 'Autoload' > press <Insert> > Add image > <Enter>
b. restart
b. you must change the path to your irfanview inside image.s
E.g. I changed:
// IRFANVIEW_EXE = 'C:\Program Files\IrfanView\i_view64.exe'
IRFANVIEW_EXE = 'G:\GRAPHICS\irfanview\i_view64.exe'
c. It is not necessary to put it in the .mac directory.
I did put image.s in my working directory and compiled
it there to image.mac.
d. Restart.
e. Then if you load e.g. (any) graphics file in TSE
(e.g. menu > 'File' > 'Open' > XMasGift.png)
It will show then inside TSE on the left side.
f. I tested it with .png files, .gif files, .jpg files.
with friendly greetings
Knud van Eeden