Bitcoin Core Re-install- Don't want to Overwrite Chain Previously Downloaded

I have a full Bitcoin chain that I downloaded using Bitcoin Core (v.0.18.0.0, from Ubuntu's launchpad bitcoin ppa). I've moved to another machine and installed the Snap linked from BitcoinCore.Org, pointing it at my .bitcoin directory. When I run it, I get the following message. Before I hit "OK", I want to make sure I'm not going to nuke my already downloaded chain. Can anyone confirm?

As this is the first time the program is launched, ... Bitcoin Core will download and store a copy of the Bitcoin block chain.... The wallet will also be stored in this directory.

[ ] use the default data directory
[x] use a custom data directory

When you click OK, Bitcoin Core will begin to download and process the full Bitcoin block chain (320GB) ....

[ ] Discard blocks after verification, except most recent 2 GB (prune)

Also, it's been a while since I looked, but the Ubuntu PPA stable channel is now saying:

NOT MAINTAINED. The OS-library linking packages here had a series of issues.PLEASE DOWNLOAD DIRECTLY FROM bitcoincore.org ...

Is there any chance running that Snap might cause any issues with my wallet and already downloaded blockchain?