Just an observation about the level of security needed - and the attendant cost to the taxpayer, either here in the UK or in Canada.
The Sussexes are said to have a security detail of "six at any one time in a 24 hour period". This actually translates to at least 24 security officers: six for each of the three 8-hour periods of the 24 hour day, plus six on rest day (security officers being humans too and needing time off). There would be additional requirement needed for annual leave, sickness, training and so on, so you are probably looking at a team of 26. At least.
In addition to salaries, there are additional accommodation and travelling costs, subsistence allowances, cost of specialist equipment and the cost of specific refresher training, as well as the cost/burden to senior staff not involved in day-to-day protection but carrying operational and managerial responsibility for those actually on the security detail.
It all adds up.
Anyone who suggests that a lower level of security would be sufficient because of Canada's relatively low incidence of terrorism is missing the point, just as anyone who believes that Harry enjoyed a normal "just one of the lads" experience in the Armed Forces.
There is no senior commander in the world - either Armed Forces or police - that would risk either an attack, a serious or fatal accident or any other reasonably foreseeable incident to someone like Harry. Not least because it would be career-ending. If normal Apache helicopter maintenance includes a double check for safety, it would have been a triple check or a quadruple check in Harry's case.
I rather think it's not the title or the money the Prince of Wales is minded to give his son from his Duchy proceeds that requires more thought. It's the how/who/how much/who pays/which jurisdiction/which applicable rules and laws for security, that's bedevilling the Queen's advisors.