Over the past 7 years as a solo ERISA practitioner, I always get asked if that’s all I do. It’s not some kind of insult, but a question on whether I also do financial advisory work and/or third party administration work. The answer is no and I stick to what I do.
Over the years, I’ve seen plan providers get into trouble by offering advice that they are not experts in. Unless they have an ERISA attorney on staff, a TPA is not a lawyer and an ERISA lawyer is certainly no financial advisor. My wife and I always chuckle when non-attorneys give legal advice and I’m sure other providers would chuckle if I gave financial and/or plan administration advice.
You should stick to what you know. It will save you and your client, a giant headache.