The RI is needed by the CM11A protocol as that initiates the handshaking process with the PC.
Actually, it operates at a much lower level. PCs that came with Serial Ports had a
WAKE ON RING setting in the BIOS but how to set this varies with PC brands, firmware, etc. And, it gets even more complicated with USB.
There is also a
WAKE ON LAN setting and it should be possible to use this with a
WeMos/LoLin D1 mini by sending WiFi to the PC when the CM11A or XTB-232 sends RI to the
D1 mini, eliminating the need to send RI to the PC.
https://www.tomshardware.com/reviews/bios-beginners,1126-8.html
Another solution might be to just use the ample Flash memory of the
D1 mini to store macros/timers, eliminating any need to wake the PC.
I'm not going to pursue this further because my health severely limits what I can do these days. However, if someone younger and healthier were to pursue the
WAKE ON LAN or Flash solutions it could be a way to convert a CM11A or XTB-232 from serial to USB & WiFi for less than $5.
https://www.aliexpress.com/item/32529101036.html?spm=a2g0o.store_home.productList_2559240.pic_2