What are the nooropics that support maximum neurogenesis

You need to start low risk, high reward, minimal effective dose. Thngs like circumin which i know you take. Magnesium L threonate (crosses bb barrier and has bdnf action). Piracetam (30+years of study, graduating too or adding Aniracetam). Forskolin to increase CAMP (natural stacks makes a nice product Ciltep). A mushroom mix (maybe chaga, lions mane a good start). Possibly a choline source but I'm going to guess you are choline dominant and it would add jaw tension. Possibly and adaptogen.. ginseng, rhopalia. Caffeine and theanine combine very well.

Deprenyl, as you age MAO becomes more active lowers your neurotransmitter levels, and in a small % of people enough to cause Parkinson's. It helps your neurons communicate and has been found to help learning.

Lets think about general cognitive enhancement and specific task support separately.
As you already know and do, supporting general cognitive capabilities starts with the foundations: good sleep, good nutrition, movement, cognitive stimulation, etc. Then, getting into supplementation, ideally this should be personalized, based on lab work, genetics, experiential testing, etc. Generally good foundational supplements for most people include:
1. Membrane support: essential fatty acids and phosholipids in particular. BioPC formula, a full spectrum fatty acid formula (like Udo’s choice), with extra DHA is generally a good idea. As is taking essential fats with fat soluble antioxidants (astaxanthin, R-lipoic acid, Vit E, etc) as they are very sensitive to oxidization. Uridine is a generally good addition here. And electrolytes.
2. Energy metabolism: MCT’s for fuel and ketone support, krebs cycle intermediaries like creatine, ALCAR, co Q-10/ubiquniol/PQQ, B vitamins, etc. Including NAD support like NR. And blood sugar regulation support if needed: zinc, chromium, vanadium, cinnamon, ALA, etc. And iron/ hemoglobin/ ferritin support if needed (should be lab based - excessive iron is dangerous).
3. Cerebral detox and and neuroprotection: Vit D, NAC, glutathione, oxaloacetate, chlorella, antioxidants (fat and water soluble, astaxanthin and pterostilbene are great starts in addition to the essential nutrient antioxidants), antiinflamatories (curcumin/ piperine, green tea/EGCG, ginger, rosemary, systemic enzymes, aloe, etc.) Also cerebral perfusion support like ginkgo, niacin, etc.
4. Key nutrients for neurotransmitter production: amino acids, zinc, B5, P-5-P, Vit C, choline donors (as needed), etc.
5. HPA axis support: adaptogenic herbs (rhodiola, ashwagnada, ginseng, holy basil, etc) along with B vitamins (pay attn to methylated forms based on your genetics) and minerals (magnesium, potassium, etc.) Can use more potent hormone modulators like PS, licorice, pregnenalone, DHEA, etc. Again, lab testing is a good idea.
6. Gut-brain axis support. Pre and probiotics, digestive enzymes, fiber, mucosal barrier support as needed, etc.
These are good foundations for nutritional nervous system support.

Moving into generalized cognitive enhancement chemistry, as far as generally well tolerated things go, most people notice the most lift from neurotransmitter pathway modulation, particularly for acetylcholine, glutamate, and catecholamines.
Acetylcholine stacking is the foundation of the nootropics world: some choline donors (CDP choline, alpha GPC, centrophenoxine, etc.), usually with an acetyl donor, generally ALCAR, with some racetam. Oftentimes multiples racetams. Can also include acetylecholineesterase inhibitors (Huperzine a most common), and extra B5, used in making acetylcholine. Many other chemicals can help the cholinergic system: PDE4 inhibitors, cAMP up regulators, PRL-8-53, etc.
Next most common is dopaminergic stacking. Precursors first: phenylalanine and acetyl-tyrosine, with P5P and Vit C. Then can add an L-Dopa source like mucuna extract. Can also get into selective MAO-b inhibition, like hordenine. Must be careful here. And very careful stacking mao inhibitors with mono amine agonists. Can also use dopamine receptor modulators like uridine. Can also use synthetics here like eugeroics, etc.
Next most popular category of receptor modulator following racetams are ampakines. Some chemicals like aniractam and noopept act on both NMDA and AMPA receptors.
This is why I made the distinction between general enhancement and for specific goals or tasks - each cognitive capability and subjective state are mediated via different physiological pathways. For instance, its quite easy to create hyper focus at the expense of empathy. Not a good general state to hang out in - but maybe ok for specific tasks.
Most of the above kicks in relatively quickly because its working through neurochemistry. Your initial question was about neurostructural up regulation - increasing gray matter density and changing connnectomic patterns via neurogenesis, synapto- genesis/cleaving/plasticity, etc.
The benefit here is you are up regulating the endogenous regulatory infrastructure so increasing the total capacity of the system.
Generally achieve through neurotrophin up regulation - primarily BDNF and NGF, but also GDNF, IGF-1, HGH, etc.
The foundations here nutritionally are things like lions mane, uridine, zinc, lithium orotate, curcumin, omega-3, etc.
many of the most exciting nootropics work through neurogenesis, like cerebrolysin, NSI-189, etc. But I would not advice these for general use until well educated.
Everything above is focused on ingestables. The most robust data on neurogenesis is from exercise, mental stimulation, caloric restriction, intermittent fasting, and sleep. Also can be affected through neurofeedback and various forms of transcranial stimulation.

I usually by from Brainstorm Nootropics, directly from them it is around $33-$34, but there are a variety of resellers, including Walmart, that sell their product for under $32.