Search not improving after ~1000 iterations

[macsz]

I did multiple runs of search and usually after 800-1000 iterations there is no improvement. Is it a desired result? Given large search space I would expect the search to require far more iterations to converge on an optimal configuration.

Example partial output of search.py:

Iter: 0 Acc: 0.8829606175422668
Iter: 100 Acc: 0.8930274844169617
Iter: 200 Acc: 0.8938609957695007 
Iter: 300 Acc: 0.8939877152442932
Iter: 400 Acc: 0.8941074013710022
Iter: 500 Acc: 0.8942490816116333
Iter: 600 Acc: 0.8942490816116333
Iter: 700 Acc: 0.8942490816116333
Iter: 800 Acc: 0.8942490816116333
Iter: 900 Acc: 0.8943868279457092
Iter: 1000 Acc: 0.8944254517555237
Iter: 1100 Acc: 0.8945743441581726
Iter: 1200 Acc: 0.8945743441581726
Iter: 1300 Acc: 0.8945743441581726
Iter: 1400 Acc: 0.8945743441581726
Iter: 1500 Acc: 0.8945743441581726
Iter: 1600 Acc: 0.8945743441581726
Iter: 1700 Acc: 0.8945743441581726
Iter: 1800 Acc: 0.8945743441581726
Iter: 1900 Acc: 0.8945743441581726
Iter: 2000 Acc: 0.8945743441581726
Iter: 2100 Acc: 0.8945743441581726
Iter: 2200 Acc: 0.8945743441581726
Iter: 2300 Acc: 0.8945743441581726
Iter: 2400 Acc: 0.8945743441581726
Iter: 2500 Acc: 0.8945743441581726
Iter: 2600 Acc: 0.8945743441581726
Iter: 2700 Acc: 0.8945743441581726
Iter: 2800 Acc: 0.8945743441581726
Iter: 2900 Acc: 0.8945743441581726
Iter: 3000 Acc: 0.8945743441581726
Iter: 3100 Acc: 0.8945743441581726
Iter: 3200 Acc: 0.8945743441581726
Iter: 3300 Acc: 0.8945743441581726
Iter: 3400 Acc: 0.8945743441581726
Iter: 3500 Acc: 0.8945743441581726
Iter: 3600 Acc: 0.8945743441581726
Iter: 3700 Acc: 0.8945743441581726
Iter: 3800 Acc: 0.8945743441581726
Iter: 3900 Acc: 0.8945743441581726
Iter: 4000 Acc: 0.8945743441581726
Iter: 4100 Acc: 0.8945743441581726
Iter: 4200 Acc: 0.8945743441581726
Iter: 4300 Acc: 0.8945743441581726
Iter: 4400 Acc: 0.8945743441581726
Iter: 4500 Acc: 0.8945743441581726
Iter: 4600 Acc: 0.8945743441581726
Iter: 4700 Acc: 0.8945743441581726
Iter: 4800 Acc: 0.8945743441581726
Iter: 4900 Acc: 0.8945743441581726
Iter: 5000 Acc: 0.8945743441581726