Lab Research Speed 5 provides no bonus over the former:
Lab Research Speed 4: (0 -> +50%)
Lab Research Speed 5: (0 -> +50%)
The whole LRS tree seems improperly balanced (starts at 20%, provides no consistent increment per iteration etc.), this part might be intentional, however?
[2.0.9] Lab Research Speed not properly balanced
Re: [2.0.9] Lab Research Speed not properly balanced
Thanks for the report however this is a duplicate of 116018.