Questions about our cocktail and radiation (at 2nd recurrence)

I posted earlier this year, after my partner had his second gross total resection (his first resection was in Jan 2017).  We did pembrolizumab and CCNU along with a relatively small cocktail of supplements (vitamin D, curcumin, PSK, bosellia, melatonin).  We tried Celebrex and my partner immediately developed colitis, which made me gun-shy about introducing more treatments.  At that point his MRIs were improving, anyway, so it seemed better not to introduce new complexity.

Then, in June and July, he had a couple grand mal seizures and his MRIs worsened.  By early August the doctors concluded that there was actively growing tumor, so were officially at second recurrence.  We stopped pembro and CCNU, and began Avastin.  I also finally introduced metformin and simvastatin, apparently without any side effects.

A scan last week was a little worse but not dramatically.  There had been significantly more progression in the 4 weeks between the July and August scans than in the 6 weeks between the August and September scans. 

I’ve gotten our oncologist to agree to let us add telmisartan and mebendazole, although we haven’t started either yet.  My partner still needs 4-6mg dexamethasone daily to control cerebral edema, even with Avastin, and I’m hoping telmisartan will help us reduce that.  I’m still not sure what to think about mebendazole.  I share Stephen W.’s worry that the mega-doses could interfere with other treatments and I’m skeptical of Care Onocology’s profit motive (they patented their 4 drug combo and threaten to sue violators).

We’re also trying to get VAL-083 through expanded access, although that’s taking a while.  My partner is not a good candidate for treatments requiring another surgery, like vaccines.  He lost significant brain function in the second surgery and also suffered major complications from seizures and blood clots.  He's very clear that he does not want a lot of suffering from here on out.

I have two questions for anyone who wants to weigh in:

1. Is there anything we should strongly consider adding to this cocktail?  My partner’s tumor is MGMT unmethylated and IDH wildtype.  Tempus showed NF1 and RB1 as the only potentially actionable mutations (I've ruled out everolimus after the study indicating it worsened OS).
2. Our neuro-oncologist had us consult with our radiation oncologist, who recommended a short course (10 treatments) of lower intensity radiation than my partner had last year, when he did the standard Stupp protocol (plus Optune after radiation).  The RO thought it might help slow the growth down a bit and provide a little symptom relief but probably wouldn’t increase life expectancy much (if at all).  We’re really torn about whether to go through with it or not, and I don't know how to gather data on it effectively.  Unfortunately, we need to make the decision fairly quickly.

Thanks in advance for your help.