As per my experience using a low pressure cap is not a good thing and leads to a number of problems such as,
Premature boiling of coolant,
Premature escape of coolant into the reservoir and eventually overflowing out of the reservoir.
Overflow from the overflow tank leaves the system low on coolant and as the engine cools, air is sucked in.
Air in cooling system is not a good thing and leads to even more problems.
IMO always use OEM spec cap. Do not worry about the hoses or radiator. If they are weak, its better that they blow up so that they are replaced with good quality proper replacement.
99% of overheating Hondas i have seen have a history of running on CNG. I currently own 2004 Vario with 132k on ODO, it does not reduce oil and never ever over heats no matter how rough you drive it. I don't think running modern engines with automatic trans on cng (especially hondas) save any real money in long term. Once they start overheating they are a huge headache.