Deep scan recovery on (old) laptop after quick format

Hello, my name is Ameey and I have a few questions about the deep scan process and file recovery. Will be grateful for any help on the following matters:

1. If I stop the deep scan after it started and recover those files, will they show up again if I run the process again?

2. Will recuva find files with less common extensions? Will they show up as unknown, with the right extension or just not at all? For example java or blender files.

Laptop. Old. 250GB hdd, C: was about 50GB. Windows just up and stopped working. I have an IT degree so to cut off-topic - I have tried everything I could think of/afford to recover the system. In the end had to quick format and re-install. Got recuva through my phone and it is now running for.. about 13h? What worries me, it's on 31% for some time. Till 29% it was going "smoothly", now the bar doesn't look like it is filling anymore, just est. time gets longer.

Stage 1 of 3, 31%, 11562 files, estimated time 1 day.

3. Should it take this long or is there a problem? I can wait if it means the scan eventually finishes, but if there is no point in waiting.. Like I said, it's 50GB so I understand it has to take some time. Just don't want to wait in vain.

// 3,5h later it's 32%, est. time 1 day, so I guess there is some progress, just an extremely slow one..

Again, grateful for any help/advice.

A. Kato