I wanted to put this out here for others who are trying to willfully enter the jhanas.

I am having good progress in doing this. I have had two recent occasions where I have entered the first jhana and, on the last occasion, I also entered second jhana*.

What I have found is that wanting jhana is hindrance nr. 1. And this wanting can be very subtle. To deal with this, I successfully used the Direct Mode grounding technique in my most recent sit where I entered the first and second jhanas. As I start focussing on the anapana spot, I simultaneously scan the stomach and chest areas to notice any kinds of clinging/wanting/grasping/contracting feelings, and when any of that pops up, I ground them in the body and they dissolve within seconds.

Here's some videos with Kenneths' instructions on Direct Mode.

* This has not been confirmed by any authority, so take it for what it is - a claim.

Good stuff! stick with it. Letting the mind reach concentration states on its own is when my practice really took off specifically dwelling in awareness itself, the observer, witness...whatever you want to call it. try to see if you can look at what is looking. this can feel like a sense of solidification in the sense of the knower, i.e. concentration/jhana (unless your just walking around doing normal every day stuff dwelling in awareness itself, not jhana then but fun none the less! )
another thing to try is while in that concentration notice how even though it is stabilizing there is change (anicca) and that intention only goes so far (anatta) and that its maybe annoying you cant go further (dukkha)
I am one who believes from personal experience that insight practice can be done while in jhana. and in this way we shed fabrications and mind leans to unbinding.

I've tried to solidify the knower aka. the Witness. And I am pretty sure that I have managed several times to do it, and it is really cool what happens. But my problem with this is that I don't know how to properly recognize the Witness until I have become absorbed in it - or rather when I exit that absorption. So, unless I somehow get it right at the start of trying to solidify that certain "feeling of knowing", I either end up with disappointment, a headache or both.

In other words, for me at the time being, the Witness is too intangible to consistently use as an object and I'm not very confident that I am doing it right. Maybe you have some pointers to it for me to check out for myself?

Yeah I gotcha. it took a while to get solidified in the witness. before I knew I was doing this witness/awareness itself practice I was doing it. or my mind was leaning toward it. I would get some stability in anapanasati then it was like my mind wanted to just dwell alone. It would feel like a pull. at first I thought I should give in because I thought it was a distraction. But, I figured, I got all this time (living at a monastery) if it goes wrong I'll just start fresh. so I made myself vulnerable and started treading into unknown territory. first I tried to locate awareness. I realized strangely yet no surprisingly that i could not. It is impossible to be aware of awareness, But, you can dwell in the sense of the knower/ awareness itself/witness. TRYING TO LOCATE (or recognize) THE WITNESS CANCELS IT OUT EVENTUALLY. and, that doesn't help if you're trying to gain concentration. so I powered back into awareness itself with an attitude of just sitting with it and letting it do its own thing and just holding on for the ride. and, what a ride it was. Now I go through the jhanaic arc in about 20 minutes forward and reverse. its fun stuff!