Can anyone elaborate on how one might do a mega-backdoor Roth conversion using a solo 401(k)? Also since I have an employer 401(k), how would the employee and employer limits work with both? Specifically if I max out my salary deferral amount in the employer plan, can I then use the solo 401(k) to make just after-tax contributions up to the annual limit and then do the Roth conversion on that amount? Thanks for any insights.