Boutique M&A / Broker

Hello,

I have recently obtained my ACA (big 4 Audit, London), and have been interviewing for M&A / transaction services positions, with the long term goal to move into corporate development, and if I have the appetite to work the hours, then eventually PE.

I have managed to secure a position at a really small boutique M&A advisory firm (self proclaimed), with about 10 people in the team. All the senior people are former big 4 corporate finance, but the junior team members are Top 10/50 accounting firms. 
 

My worry about this position is, when I have told other recruiters about this company, they’ve all told me to be careful and do my due dilligence about the role, and mentioned them being M&A brokers not M&A advisory. Of course other recruiters have self interest to put me off this role. The firm itself consider themselves M&A advisors and the interview was quite heavy on financial analysis (little on valuations).

My question essentially is, if I were to accept such a role would my exit opportunities to other boutiques/MM/big 4 CF/Corp Dev, be hindered quite drastically. Also, if I were to take a modelling course would this be enough to allay future employers fears of my technical skills? 
 

Thank you.