Olster - Modular is certainly the way forward. Ability to decide on the pace of your training and the flexibility of working around it can be invaluable especially in these times. If he is looking to start is training, my advice to them would be to start the ATPL theory with books to get a better understanding of the subjects, will save him a lot of time later when the clock is against him.
In terms of L3Harris I can't say I ever went. I did apply for the easyJet MPL 4 or 5 year back when it was still CTC. And I must admit at the time I liked them as it felt pretty slick, even if you did have to pay through the nose to get on the course or even to interview. Looking back I was probably lucky to never go.
I have met a few people who went there. Very few outside of their media lot, don't seem to have much positive to say about their time. Issues with the costs, staff, aircraft access and the like when in New Zealand. Or those who went to the US had issues with aircraft reliability in the heat. Often seemed to have gone tech, apparently one had an engine failure on their solo early on.. but I can't prove that so it's just hearsay.
Although I am aware of the Virgin lot, a few of them ended up at easy to basically hour build. Then COVID happened just as they moved to VS, not sure they're employed now.
What I do know is some who were able to get out went on the FTE and comparatively sung it's praises.
It's a shame, L3 bought it thinking it was a cash cow, grew the costs, took money out the school, problems happen and end up turning it into a lame duck they're now trying to sell. The letter just goes to show much the brand has fallen publicly.