- Don't exit to the map screen for whatever reason because if you have levelled up, the level-up animation will waste precious seconds.

This is while you're doing the mass evolve, don't go back to the main map screen. During my first evolve, I did so to check on time remaining. Because my level has gone up, the Level Up animation started and wasted some time. So you don't want to do it. Just keep evolving until the 30mins is up. I use a separate phone as a 30 min timer.

30k XP is quite low. That's only 30 evolves with lucky egg active or 60 evolves without a lucky egg. Did you activate your lucky egg before you start?

Nope i did not use the Fav function, and i even spent time trading off pidgeotto to get more pidgey candy

Thanks, I missed out too on the 10 coins the first time I beat a gym. Thought have to wait 21hrs before can claim. LOL.
No prob, each evolve will give you back 1 candy.

Results of my 4th Mass Evolve.
76 evolves + 2 new Pokemons = 78000XP

1.  You can only claim once every 21 hours.
2.  You can claim as many 10 coins as there are gyms you are holding at the time when you claim.

So, to answer your question:
If you have not claimed yet, then yes.

the reason I asked is because I already caught Pidgeotto. I read somewhere that you get more XP if you evolve to something you never caught.
so I'm not sure it's worth evolving to something I never caught, like Pidgeot and Gengar.

it may come as a surprise but I don't see a lot of caterpie and weedle. Pidgey is more but still not that many.

I got most Drowzee candies (310), Ratata (258) and then Pidgey (244).

currently I can do 47 evolution. I'm waiting until 60 then I'll use lucky egg.