たところで・～たはいいが: the difference
たところでN1
Meaning
Even if ~ cannot or will not, Even though ~ not
Past papers
Tested once in past papers
Example
徹夜で勉強したところで、合格しない。
Even if I studied all night, I would not pass.
～たはいいがN1
Meaning
It's all well and good but...
Past papers
Tested once in past papers
Example
社長に褒められたはいいが上司から妬まれそうだ。
It's all well and good that I was praised by the company president, but it seems my boss is going to be jealous.
How to tell them apart
「たところで」: even if you do it, it is pointless (see 「たところで」).
「たものの」: a neutral turn, 'I did it, but reality differs from the plan': 「大学を卒業したものの、就職難だ」.
「たはいいが」: very everyday; you did it on impulse or with high hopes, then found trouble and cannot see how to finish. It carries annoyance and self-mockery.