The reason nobody mentioned the San Miguel is because it doesn't have any water. It flowed at a "boatable" level for all of about 3 weeks this year...
You would probably enjoy the lower Taylor, although the water is quite low there as well. It looks like the spot you have marked on the map is possibly South Bank? There are official access areas for the Taylor which have boat ramps and bathrooms. You will be fine to put on anywhere though as long as you are below Harmel's and Wilder on the Taylor (private fishing ranches).
I haven't floated it, but I don't believe there are any major obstacles between the 3 rivers confluence and the Gunnison playpark, I believe there is a messy class III rapid below town though.
What it boils down to is you only have 4 drainages in the state which currently have water. The Colorado (including the Blue), The South Platte (which brings it's water under the divide through a tunnel from the Blue), The Gunnison (including the Taylor) and the Arkansas.
GARNA’s mission is to foster stewardship of the resources of the greater Arkansas River region through education, volunteerism and experiences. https://garna.org