Perhaps SSH via USB-cable to your Android does not work, due to the wrong adapter. Here are some connection methods described, which work for SSH: 5 вариантов подключения к CMU Mazda — Mazda 3, 1.6 л., 2015 года на DRIVE2 (in russian, but you could eg. use Chrome`s automatic translator). You have to use another fixed IP-address and port, like mentioned there.
For me SSH worked via USB-Ethernet Adapter with an Asix AX88772A-Chip to my notebook/laptop. I think I had to give the adapter a fixed IP-address.
Also it worked via WiFi Hotspot created by my mobile phone (MZD and notebook/laptop were connected to it) and then using SSH via notebook/laptop.
No, sorry. I have no experience with Castscreen. Perhaps others can help.
Tipp: If the original Android Auto (AA) setting can not be activated again, you have to do a factory reset (or reinstall of the FW) to activate iAA again. That was in the early FW 70 the case - I do not know, if it is still necessary at .335 - hopefully not.
The only thing I heard about, which slows a CMU down, are too many dump files or no space left at the root partition. Perhaps it helps to delete dump file via usb tweak (not at the root partition) or to free space at the root partiton via SSH. See e.g. this thread for some more info:
CMU - RootFS is Full 100% - how to fix it ?
Oh, and for the root partition you could delete some fonts - see e.g. this post:
Thank you for the reply @Tristan-cx5. You are the man. Because I might overheard the overheat issue that cause by out date earlier than version 1.13. I think should be the for V70 above. Because I worry it will fried my CMU and I need to pay thousand to get a replacement just for a short term enjoyment of Android AutoI do not have AA 1.15 and even if, I would not share, as everything related Radarwilds developments like 1.14/1.15 got banned/deleted in this forum. Perhaps someone can send it to you via PM, but I can not.
I am not aware of all the bugs AA 1.13 of AIO 2.8.6 has, as I use original AA since many years now, as this was back then much more stable. Just search for the users posts sharing/reporting their experience with AIO AA - there should be plenty in this forum. From what I know .502 should be the most stable FW for AIO AA 1.13.