Use 1st edition as a way into expanding 2e Road to Legend content? Can it be done?

Hi everyone! I'm really enjoying the Road to Legend app, and I'd like to add more content... ...BUT I only have the 2nd edition base box. 2nd edition box expansions (e.g. Shadow of Nerekhall) and hero and monster sets are crazy expensive on ebay right now. (Well over 100 USD before shipping internationally for a Hero and Monster collection etc.)

However, if I got the 1st edition conversion kit AND FIRST edition box (which I think had 20 hero miniatures and 60 monsters (BGG: https://boardgamegeek.com/boardgame/17226/descent-journeys-dark )

...would that allow me to replicate some of the 2e Hero and Monster sets and 'add' them into the Road to Legend app 'my collection's screen?

Would that work? Are the Conversion Kit hero cards dramatically different from their 2e equivalents?

(I can get a 1st edition set and a conversion kit cheaper than a single 2nd edition expansion on ebay).

Any thoughts and help on this would be greatly appreciated!

Thanks in advance.