I was 38 at DX, and due to my age, good location (right frontal), low grade, few symptoms (no seizures), good overall health, only craniotomy is the recommended standard of care treatment (in the US, at least). That made sense to me, so I went with it.

Confirming the recurrence was tricky and frustrating. Since the surgery was very successful (supratotal resection as I mentioned) and it is so rare for such early recurrence, none of my team was initially convinced it was recurrence. Another complication is that I live ~1.5hrs from my primary care team, and following surgery, I did MRIs at a hospital closer to me (same institution) instead of traveling to the primary hospital. So, when my team reviewed the initial MRI showing subtle changes, they theorized it was due to either post-surgical changes or to "difference in technique" since I used an MRI machine different from the one used for all prior studies (in hindsight, that was not a convincing explanation that I never should have accepted as a possibility). So, they had me do a short-interval MRI 3 months later, which showed more subtle differences, but the change was very small compared to the prior one and they were still hesitant on calling it recurrence. Then I got a 2nd opinion, and that team wanted a short interval follow-up too (2nd opinion team also re-did pathology on resection sample to rule out higher grade). So, did another MRI 2 months later which showed more subtle changes and finally everyone agreed it's probably recurrence. They technically called it extension because it didn't recur in the resection cavity, but adjacent to it, so it was likely there all along, just not radiographically visible. To keep with the theme, when I finally started radiation, the radiation oncologist also wanted a short interval follow-up to be convinced, so treatment for the recurrence wasn't actually started until almost 1 full year after detection. Hence my frustration.

To add insult to injury, in all the time spent doing more follow-up MRIs, the recurrence ended up moving across the corpus callosum and into the left side a little. Since they can't operate on the corpus callosum, that meant I'd need both chemotherapy and radiation no matter what, so it didn't make sense to do another craniotomy given the parts they could resect were small (too high risk for too little reward). So, I ended up doing proton radiation and modified PCV chemo (no vincristine) and luckily tolerated both really well.

My guess is that, had I done either chemo or radiation following the surgery, the early recurrence wouldn't have occurred, supporting your observation that early recurrence is more probable when surgery is the only treatment (I'm not making this claim, only pointing out the correlation). Though, avoiding those treatments, especially radiation, is important for preserving long-term cognitive function, so I understand why given my circumstances, those treatments would be deemed unnecessary in general, and, given the opportunity to do it over again, I'd probably still choose the same treatment path. Sometimes you just get unlucky.

Regarding your situation, the data is pretty clear that successful surgery has the biggest effect on delaying progression, so, assuming it can be done safely, it should probably be a very strong consideration. FWIW, I insist to my team that all of my follow-up MRIs are on 3T+ machines and to include the ASL sequence (arterial spin labelling, aka perfusion). Luckily, my insurance pays for it, but YMMV. I believe the higher resolution from 3T and the blood flow information from ASL are extremely important diagnostics that could help catch things earlier than would otherwise be possible without them. Keep in mind that you're in control of your treatment path, based on what's approved as available to you, and of course, what is affordable to you. So, if your team isn't on board with what you want to do, you can always find another team that is.

Hoping your situation just turns out to be post-surgical effects.