If the mountings are under pressure, will this prevent the lift you'd wanted? Will it lead to early failure of the mountings?
General advice when replacing lower arms or any suspension bushes/mountings, is to have the car sat on them before final tightening. This puts the flexible mountings in their normal 'at rest' position, so that they flex evenly form there. If not already done, might be an idea, with the car sat on its wheels, to slacken all the mountings and retighten, to allow any stressed rubbers to relax.
If you are carrying a lot of heavy stuff, might be worth weighing it to ensure not overloaded. Whilst the load may be less than carrying people, the position may need adjustment to even it out.
Good advice, I shall indeed check. The reference to not dropping down far enough was to do with getting the spring out of the way to be able to seat that spacers confidently, so won't affect the ability of the kit and mounting to do the job for which is was designed.