Hitchhiker is perfect for spar work, I went to the roperunner now and I miss the hh2 on the spar. The runner just feels like it could get side loaded or something, probably just me worrying too much but the hitchhiker is bombproof and instilled confidence.
Before I went srt I used a rock exotica mini 8 and locked it off. Another cheap and easy way is to tie a hitch that I have no idead the name of with a good heat resistant cordage, it allows you to run a single rope without any additional friction. There's a thread on tree buzz about it. I did one climb on it just to experiment and it works pretty well.
I use a steel oval autolock for that purpose. Either use the spliced eye if I am just spiking down a few feet at a time or a butterfly knot with enough tail to retrieve so I can descend on rope when taking bigger pieces or coming down to fell the stick.