When I do SRT I girth hitch in the canopy, usually the trunk vs suitable limb, no basal anchor. I use 700lb paracord as the retrieval line, never once had a case where I couldn't get the climbing line down. I carry 50' of oplux/resc-tech with a friction ring on the loop and 50' of paracord, 100ft zip line and 12oz bag. If I can't get in the canopy with that I find another tree...
Instead of a belay device, hand ascender and pulley (RAD components) though, I just use one JRB hitch on my main bridge and a foot loop with the ropeman on my short bridge.
To climb I tend the foot loop to get my knees bent, hold the rope in one hand below the JRB hitch to steady myself, sometimes I'll hold above the hitch if I'm mostly hanging in free air and can't use my other foot to help steady myself on the trunk. Then stand on the foot loop and advance the JRB hitch with the other hand. Settle into the bridge to lock the JRB, advance the foot loop, grab rope, stand and repeat. No mechanical advantage, but I advance up the rope in longer strides because I'm not limited by the 3/1 ratio increments of a RAD system.
To climb this way you could effectively replace the JRB hitch with a hand ascender and accomplish the same thing with the exception of not being able to rappel without transitioning from the hand ascender to a rappel device. JRB hitch does both, so one less operation involved.
To descend you simply replace the foot loop on your short bridge with an autoblock or figure 8, slowly break the JRB hitch and rappel.
I've rappelled by breaking the JRB hitch and managing the tag end by hand(with gloves), no figure 8 or autoblock too. But don't recommend it as a standard procedure. However in some kind of emergency its possible to safely get back on the ground relatively quickly, as long as you remove the foot loop to avoid jamming into it on the way down. Just gently breaking the JRB will allow you to descend very slowly, release the break and you stop.
I think this sort of thing is good to practice at low heights as part of your self rescue regimen in case you needed to do it, like dropping your figure 8 and no extra carabiner to do a munter, etc. Even if you dropped your foot loop and the JRB hitch jammed you could tie an alpine butterfly with a loop large enough to put your foot in to unload the JRB hitch, fix it, untie the butterfly and continue on down. No extra stuff needed to get out of a bind...