@DoubleTrouble99
Agree that EU FoM favours EU migration over rest of world and accept that an abundance of cheap labour (native or foreign) likely suppresses wages for low-skilled roles at least to some extent - think there are BoE and LSE studies showing this effect is minimal though. Accept that FoM means that there is a large supply of cheap(ish) foreign labour available to UK businesses - note RoW labour pool is presumably cheaper than EU i.e. minimum wage or less if employer willing to break the law. Agree that with current rules, only a withdrawal from SM (i.e. no-deal or Canada-type deal) would end FoM and return immediate control of immigration policy to UK gov.
Problem is with Brexit as the solution to these issues, both in terms of effectiveness and the balance of costs/benefits. Don't think we can avoid immigration at low-skill end of the market - e.g. UK has aging population that needs care services, UK labour force not likely in short-term to take up agricultural roles (even with wage increases), etc ... Result - immigration continues to happen from RoW (and some EU) thereby continuing to suppress low-skill wages and continuing/exacerbating cultural issues arising from mass migration (suspect many leavers would be more comfortable with EU migration than RoW).
The cost of leaving the SM without some form of low/no friction border (across UK not just NI) will likely result in substantial UK JIT manufacturing & aerospace job-losses (100,000s jobs) at least. Personally think it'll likely be worse with finance, pharma, IT, agriculture, fishing, etc ... all affected adversely in one way or another. Overall effect - big recession and widespread misery for us and most importantly our DC for many years. Moreover, in the longterm, UK will be systemically disadvantaged without benefits of collective bargaining and without the benefits of frictionless access to larger markets such as EU, NAFTA, etc ... most international businesses (inc. UK operations that get big enough) will look to base themselves within these areas. Worth noting, that only these large area trading blocks have sufficient impact on multi-nationals to contain/influence their poor behaviour (e.g. tax avoidance).
EEA/EFTA+CU with staged 10+ year exit roadmap and top-down drive to decouple UK economy from EU would at least avoid deep recession. Better still remain - make common cause with other nations with concerns over EU freedoms - set sensible limits, keep freedoms for our DC within limits, keep UK manufacturing (or even expand it after Brexit is forgotten), retain our IPR and leadership within EU, etc ... Accept that its a big reverse and alot to ask of leavers but better that than knowingly forcing UK DC into a bleak position, no?