Stay at Weak Dealflow Team or Lateral?

Ignore title, currently ASO3 at a well regarded MM (WF type). Have a very good life, work 50-60 hours a week for the most part, paid street comp. Been with the group for a few years now and am on track to get VP promotion. 

However, my coverage group is very weak in M&A. Most of our fees come from balance sheet products or buyside financing. When we get M&A mandates the deals are typically much smaller than deals other coverage teams work on at my bank (typically $200-$500M EV, with a few in the $1B+ range). When we talk internally about fee opportunities with sponsors we basically almost always write off sell-side M&A b/c we know the sponsor won't give us the mandate.

If I'm interested in a long-term career in banking but the lack of M&A experience is starting to worry me. I started at a much more M&A focused MM (Blair, Baird, etc.) so I know what it looks like when a team has a lot of M&A flow. 

I do appreciate getting access to the balance sheet products b/c it just makes banker development much easier, but I don't want to just do that forever and feel that is not conducive to a long-term career in IB. 

I could relatively easily lateral back to M&A MM world or to a mid-tier BB. But I like my team, have a strong reputation internally, and feel we have a great culture / WLB compared to some of my peers at BB/EB. Seniors are very supportive and I've started building out my own sub-coverage. 

Any perspectives here would be very helpful.