I really like the connectors on the US Digital S4/E4 series encoders. Browsing around on their website, it looks like it's a 1.25mm pitch Molex PicoBlade connector.
https://youtu.be/0bRyezC_P0M?t=141
The big thing I enjoy about them are the friction locks, they feel much more secure than standard 0.1 header connectors. I wouldn't mind a bigger pitch than 1.25mm though for FRC use though.