It took me 2 days to understand some of Leica's illogical design put into Leica T (T) menu (firmware version 1.9)
If you want to set up your T with a cheap (Fotasy) Chinese made M-L adaptor to mount your M-lenses onto the T and manual focusing the lens, you will need to activate the image magnification feature to achieve your critical focus. There is NO focus peaking feature on the T (latest firmware version 1.9 in 2025 !).
1) Note that we cannot choose M (Manual exposure) if you want image magnification.
2) I choose S (Shutter speed priority) ( P, A modes are also permitted) on the Right dial
3) Move the Left dial slightly to turn on and then touch the top right screen the dial choices selections in order to map the Focus Aid to the Left dial.
4) Choose Focus Aid On in the displayed menu.
5) So now your Left dial is the focus aid (image magnification to 3X and 6X) for critical focus when you move the dial left and right as you focus manually the lens.
Hope this help others who are perplexed by Leica T.