Hi @houndstooth
Not sure what you mean: LAN 'smb' sharing have been around as a shipping feature in OSes for 3 decades (30 years). It continues to be in Windows, MACs, Unix, BE, Linux, etc., out of the box (OOTB) for 30 years with the world participating to make this technology as safe for local LAN as possible.
SAMBA is merely the Linux version of 'smb' technology since 1992 developed by an Australian to compliment the work done by a New Zealander. The worldwide development community continues to contribute to this ongoing effort in exactly the same way as done for Linux kernel development.
The PUPPY and forum implementations are done with the same security concerns as all others who use the 'smb' standard.
I am NOT the spokesperson for either the kernel or the smb technology we have in PUPPY, but as far as I can tell, this use shared with you in your PUP distro is safe and easy no matter if you use a wired topology, a wireless topology, or a combination of both.
Please do not confuse LAN's wireless with LTE cell wireless as they are NOT related in any sense of technology.
In closing, Android with a smbclient of some sort, whether built-into an app like a filemanager or a media player should be considered safe use with your PUPs via its SAMBA. You control the users and the passwords for how and what you share on your home LAN with the LAN neighbors PC/equipment you have:. Thus, if you choose the OOTB security or if you choose to extend beyond, you have the ability to control it.
This post may/may-not make you feel any more safe, but, in my many years using this stable technology with all of the varied OSes I have used in my lifetime, I find it simple; and with @01micko's implementation for PUP use, it is much simpler than MACs or Windows to implement, OOTB.
Hope this is helpful info.
Edit: corrected mistyped starting year.