I wrote a package last year called 'inflection', its detailed on www.inflection.top, but I have been working on this problem since 2012, and I was an early miner, but I always found BTC-HACKING, e.g. solving the 'discrete log problem' more interesting than accumulating btc.

All the things you have asked for have been done,

But I might add that 'brute force' hunting is not the way to go about this problem, like the other guy 'LBC' linear collider, its stupid to search 1-N, where N is 2**256, as that is counting all the atoms in the universe, many times over. It can't be done, unless you have an infinite time-frame to solve the problem,

The way to go about this is INTELLIGENT selection of the seed for searching the frames ECDSA, also using SAGE and MSEIVE ( most powerful factoring tool on earth ), you can factor public-keys, and develop a good band for your search, also using FFT, and RNN-LSTM you can generate favorable regions for searching,

My software that supports all GPU HW, currently does 150M/sec calcs per 1060 class card, so on a typically GPU rig for mining, I can do over a Billion calc's per second, but that is still just 10***9, where our scope is say 10**77, and there are 10**71 atoms in the universe.

Also I don't think its possible to find a particular key for a particular address, the way to go about this problem, is I have 200 million addresses with value, and 100k with high-value, I use a four layer hierarchical bloom-filter that starts at 2*32, and goes up to 2**40, everytime I find a priv-key that matches my list, there is 0.0000001% chance of false-positive, that one in 10 million, but I'm doing a billion a second, so I'm geting a lot of false positive hits, so as candidates are found, they past to the next heirarchy of bloom filters, so I can kick out up to one in a billion false-positives, I usually dial this stuff in so I can about 100 candidates a day, then its easy to use the database online to check if the key found has a 'current value', if > 0, then I log, I have found lots of 0.001 BTC, but the odd's of finding > 0.01 BTC are low, as we're talking 2*22 in a space of 2**128

So in reality here I'm looking for 200 million keys at once, not looking for one, and I'm using best estimates of likelyness to search in spaces

I think the most progress will be made in the area of sage/msieve using the published papers on discrete-log problem solving, if you want to find a particular key for a particular public address. Right now I have it down to 2**42, which is still to long to search, but with 2**24 at once, my search space is only 2**22, which is no problem