incrasing that value made the snapping less accurate and I'm unable to place them where I want them
Could you describe this problem more specifically? Please take into account, that floating point numbers cannot represent decimals all precisely, hence if you set some values like 0.3 they might actually get changed to 0.300000004
Increasing the value creates gaps when snapping
Are you sure you set the value to the exact size of your modules? If so, could you send me a screenshot such that I can investigate this?