How to have a licence for occasional use scenarios, when subscription is not feasible?

I'm using TeamViewer to connect to my blind friend to help her with computer issues when her screen reader cannoot help.

Mostly she can get along without help for months and then one weekend she might need lots of help to set up some software.

But sometimes TeamViewer reports being used commercially and blocks the connection for minutes or limits session time. I'm not sure why it happens - maybe because we both have an ISP that provides dynamic IP addresses, and one of the addresses might be in some kind of TeamViewer's blacklist or something like that.

Anyway, I don't care what the reasons are and I don't want to start solving those issues with TeamViewer support because, as I've seen from other posts, sometimes the commercial trigger can get upset by unknown factors and there's nothing I can do to resolve the issue in minutes, while my friend is waiting for help.

So, I was ready to pay for a TeamViewer licence but I was very disappointed to find out that it offers only subscription options. Paying for entire month is totally unfeasible in my case when all I want is just a few weekends of use without any interruptions.

Please, please, TeamViewer, bring us an option to buy a permanent, one- time-payment licence for such use cases when we need TeamViewer for a few days only. Thank you for the awesome software, but until there's no reasonable way to pay you I'll have to use your competitor's software which is inferrior.