Slitherine

It would be good if there was a facility that showed one's units that have been destroyed and allowed one the opportunity to instantly repurchase them. It would save time taken looking through one's unit list to see exactly what's been destroyed and also in going through the purchase menus.

It's similar to the 'reform unit' option but that only seems to work in campaign mode and from what I can tell you can't re-buy the unit during the game.

I would also like an option in playing scenarios (mainly for multiplayer) where one would only be allowed to re-purchase units that have been destroyed and not purchase any different ones.

Check out the new "reform units" feature

As I wrote above, that seems to only work in campaign mode. I tried it in single scenario mode and the units didn't return to the Reserve Pool. I then tried it in campaign mode and they did go to the Reserve Pool but I couldn't find a way to instantly buy them back (unless I'm missing something).

Uh... Why would you need them back in single mode? There's no followup scenario so... I don't really understand what you're trying to do here. In a new single scenario you get fresh units everytime...

Say I lose five units in a turn. Currently, if I want to replace them all with the same units then I have to go through my unit list and make a note of what I've just lost, trying to remember what I had before. It would be good if they re-appeared in the Reserve Pool and I would then be able to click on them and repurchase them.

In 1.21, they all show at the bottom of the list.