10 year Visit visa for mom

[sbr]

I am looking to apply for my mom's visit visa. She has been visiting me since 2008 and has spent about 4-5 months each time. Never broke any rules. In order to plan her visits better, am thinking of applying for a longer term visa. The reason being it would cut out the paperwork each time, help me plan a shorter trip (3-
4 months) and probably book when fares are low.

If I give the reasons above, what are the chances of getting a long term visa?

Thanks

[Wanderer]

I'd say low.

4-5 months isn't a visit and UKVI seem none to keen on extended stays lately.