OpenCL: Custom MaxDuration from john.conf isn't halved in initial GWS tuning, and seems to be limited to original value.

Normally when a kernel is autotuned with a max_duration of 200, that figured is halved for the initial GWS tune:

Benchmarking: Bitcoin-opencl, Bitcoin Core [SHA512 AES OpenCL]... Loaded 13 hashes with 13 different salts to test db from test vectors
(...)
Calculating best GWS for LWS=32; max. 100 ms single kernel invocation.
(...)
Calculating best LWS for GWS=65536
(...)
Calculating best GWS for LWS=256; max. 200 ms single kernel invocation.
(...)
LWS=256 GWS=34816 (136 blocks) DONE
Speed for cost 1 (iteration count) of 200460
Raw:    10582 c/s real, 10614 c/s virtual, Dev#2 util: 100%

Problem 1:
If I decrease the default using Bitcoin_MaxDuration = 80 in john.conf, the figure will be honored but not halved for the initial one:

Benchmarking: Bitcoin-opencl, Bitcoin Core [SHA512 AES OpenCL]... Loaded 13 hashes with 13 different salts to test db from test vectors
(...)
Calculating best GWS for LWS=32; max. 80 ms single kernel invocation.
(...)
Calculating best LWS for GWS=65536
(...)
Calculating best GWS for LWS=256; max. 80 ms single kernel invocation.
(...)
LWS=256 GWS=34816 (136 blocks) DONE
Speed for cost 1 (iteration count) of 200460
Raw:    10614 c/s real, 10614 c/s virtual, Dev#2 util: 100%

Problem 2:
If I increase the value instead using using Bitcoin_MaxDuration = 400, it seems to be limited to the original value and silently ignored:

Benchmarking: Bitcoin-opencl, Bitcoin Core [SHA512 AES OpenCL]... Loaded 13 hashes with 13 different salts to test db from test vectors
(...)
Calculating best GWS for LWS=32; max. 100 ms single kernel invocation.
(...)
Calculating best LWS for GWS=65536
(...)
Calculating best GWS for LWS=256; max. 200 ms single kernel invocation.
(...)

Reproduce the OpenCL autotuning output with Bitcoin_MaxDuration set to 80, 200, and 400 in john.conf, then trace how max_duration is applied during the initial GWS and later LWS tuning. Done means the configured value is consistently handled as intended in both tuning stages, including values below and above the default.