I happened to be browsing the forums today, and I checked this one and seen your post. my last post which was just before yours was in 2017.
I have an answer for you even today the RS-TX20 and RS-TX60 (the same machine, different size hard drives) are useful, even if they aren't activated, these machines came with something called "Tivo Basic" Now Support could be pulled from Tivo at any time, but mine still work with Tivo Basic which does not need an account and is FREE. which gives you only 3 days of the guide info vs I believe it's 14 for the paid. So here is what it can be used for.
1. A DVD Player (it can stop on a dime and give you nine cents change, I have never seen any DVD players that are as Precise and User Friendly as These Tivo Units (Do note they can only play DVD's not Blu Rays It can also play Standard DVD-R, but I don't think it supports DVD+R
2. If you have Cable they can be set up to control a cable box with an ir emitter so you can continue to use it, even though most cable has become digital and often requires cable boxes.
3. These units would have become useless for OTA after the Digital Transition, but Tivo fixed that with an update to the operating system, that allows you to set the unit up through the composite inputs to control a small number of digital converter boxes that it can control. I have 2 of the most popular the Zenith DTT 901 and the Magnavox TB100MW9. This list shows a number of boxes that the Series 2 Tivo units can control, but it can probably control more now as some manufacturers may still be using the same remote codes.
Tivo Customer Support Community
Here is how to hook it up
Tivo Customer Support Community
4. These Tivo Units once something has been Recorded to it have the ability to save the recording (Provided it's not to large) to a Blank DVD-R. It does it pretty fast and give it a nice Tivo Menu so that you could play it on any DVD Player or computer but it looks like a Tivo.
There are 4 Recording Qualities Best, High, Medium, and Basic.
Recordings recorded at Best Quality can fit 1 hour on a DVD
Recordings recorded at High Quality can fit 2 hours on a DVD
Recordings recorded at Medium Quality can fit 4 hours on a DVD (my pick)
Recordings recorded at Basic Quality can fit 6 hours on a DVD.
5.Yes you can record things on it either through a cable box, or an Digital Converter Box for OTA, or either Composite or S-Video. and you can record manually.
The Quality can be very nice to watch even on Large Televisions,
However due to hardware limitations it is impossible to record these in HD.
And again even if there is no "Lifetime" on this unit, these units at least for now come with Tivo Basic and can work, get 3 days of guide info from the internet and don't need an account to do so.
IF you like it use it, Otherwise this can be used as a single tuner Cable or OTA DVR for someone who doesn't have one
and it won't cost any monthly fees. in order to use it, you would need the Tivo Unit, a Wireless adapter to get the guide info from the Internet, an IR Emitter to change the channels, and the appropriate cables to hook up the unit to a TV to watch and a Cable or DTA OTA box to control for cable or OTA Recording.