One thing I did for RC that brought me from a 162 to a 166 (I didn’t change anything else) was writing a one sentence summary for each paragraph. It really helped me synthesize the info and focus because I found the passages kind of boring tbh and it was hard to focus on them. Hope this helps and good luck!
If you are 100% working for that partner, you may very well find yourself looking for a new position when that partner retires. If you think their retirement is not far off it would be prudent to either try to diversify your practice by working for other partners as well, or be proactive and look for a new position before that is forced upon you.