SWR Tap2Go and split ticketing - Have I made a mistake?

[Fiyero]

I have a SWR Eastleigh-Winchester Annual Season ticket on a Smart Card. I saw the big signs saying railcards an now be added to Tap2Go so added it and have had my railcard approved. I thought it would be great for things like going to Southampton or Hedge End and not having to use a paper ticket or even load a ticket!
I then had a thought about some linked scenarios. When I go to London I only need a ticket from Winchester to London.

1. I sometimes split ticket, I am certain it won't give me this 'best price'
2. In a few weeks there are engineering works, I have already booked my ticket to go via reading to Paddington. I started the ticket from Winchester but won't have the chance to tap out at Winchester, not formerly an issue.
3. It is sometimes cheaper for me to get an advance from Winchester to Waterloo, again I wouldn't tap out.

Are there any ways around this? I am going to try it as my first few journeys aren't affected (other than not saving a couple of pounds by split ticketing) and it will be useful on the small trips but wonder if I may need to end up cancelling it

Follow up. Can I buy tickets and load them to my card first? For example add an advance ticket so a journey is covered by my season ticket and the advance so no extra charge is needed? I’m sure I have done that before on the SWR app but not sure how to make it do it.