However, he told the committee there were still "troubling" systemic issues at some hotels and that included substandard exercise areas and access to fresh air.
He said he would especially like to mention his concerns about the Grand Mercure on the Terrace, where the only space available for exercise is an underground car park.
"I don't want to be dramatic but even others in detention - that is detention because they have done something wrong - are better treated than this. We have kept the pressure on in relation to that facility, which I hope comes to the end of its natural life sooner rather than later."
At some facilities, Boshier said it was difficult for returnees to access pain relief like Panadol, because of overly pedantic rules around low-level medication.
Meanwhile, the standard of care for some unaccompanied young people going into MIQ facilities was less than satisfactory, he said.
"They can be especially challenging in their psychological needs. Some do have actual conditions such as autism. We have wanted to stress the real obligation that we, the state, have to ensure that young people who are detained - only because of the need to control Covid-19, they have done nothing else wrong - are accommodated as we would expect of the United Nations Convention on the Rights of the Child. Over and beyond what might be done for and be available to adults."
With regards to staffing, he said the staff rotation every six weeks had resulted in uncertainty and a lack of consistency.
"I understand that permanent managers are going to be brought in and there will be a new style of operation, but I want to keep a close eye on this to make sure that it does happen as promised and that it works well."
Chairperson of the Economic Development, Science and Innovation Committee Jamie Strange asked if Boshier had seen evidence staff were actively trying to refine the system.
Boshier said yes, and stressed that his criticisms were about the system itself, not directed at individual staff.
"A number of staff who have worked on MIQ are not treated well by others in the community, almost treated as lepers. Some friends have cut them off and said, 'we're not coming near you because you work on an MIQ facility and you could be carrying something we don't want'. But we have found MIQ staff to be really well-intentioned and to have the right spirit to want to make change and to be communicative."
The Grand Mercure in Wellington - and its underground car park - were earlier criticised by University of Otago public health expert Professor Nick Wilson who believed it posed a heightened risk of spreading Covid-19.
University of Auckland aerosol chemist, Dr Joel Rindelaub, said it was about 20 times easier to spread the virus indoors than outdoors.
"An underground carpark is not going to have the same ventilation as somewhere outside and people doing exercise mean they're going to have increased respiration, means they're going to breathe more, there's going to be more aerosols around so it's definitely much higher risk," he said.
"I would try to avoid that car park for certain."
Speaking to the committee, Boshier said MIQ facilities were brought in under urgency and the decision was made to repurpose hotels, as a way of detaining returnees.
"I think the downside to that is the lack of consistency and standard, so you'll get some facilities that people go to that think that they're quite acceptable. You can, for instance, go out on a balcony and you can have fresh air,"
"Our disappointment is that some facilities don't meet the test of being fair and reasonable to those that are simply there because we require them to be, for health reasons. I would have liked to have seen a faster change in the standard of some facilities that we've felt have been substandard."
Following a report by the Ombudsman published in August, Joint Head MIQ Brigadier Rose King said "a great deal had changed."
"MIQ accepted all the Ombudsman's recommendations following the inspections a year ago, and he noted he was pleased to see we had already implemented or started work on a significant number.
"We were pleased that the Ombudsman's report noted the professionalism and commitment of MIQ staff, their proactive support for the mental health and wellbeing of returnees, and their efforts to help returnees connect with family and friends outside the facility."
