Good ideas!

Going half-speed is a great option, but I think it's important to note that going half-speed with the left side of entire guide after entire guide is not usually the best pacing unless you have a child with special needs to consider. Going half-speed in a guide is a way to help dc
grow into a guide. It can be done for 2 full years if need be, or it can be done for as little as say 2 weeks just to get dc used to a guide. If you are going half-speed year after year with the left side of the plans, and full-speed year after year with the right side of the plans, the left side of the plans will soon be inappropriate for your dc as their right side pace will have moved them past what the left side has planned. If going half-speed year after year is necessary, it is likely that a child was placed far too high to begin with, or that a child is not moving forward as they should. I hope that makes sense.
So, going from your example, if you choose to do Beyond's left side for 2 years (half-speed), but do Beyond's right side for 1 year (full-speed), in order to help your child be ready for Bigger Hearts, I'd probably do it like this:
Year 1:
Beyond Spelling List 1, Beyond Emerging Reader's Set, Beyond Storytime Boy Interest, Beyond Math 1A/1B, Beyond 1 x a week Grammar,
Year 2:
Beyond Spelling List 2, Beyond DITHOR Level 2/3, Beyond Storytime Classic Set, Bigger Hearts Math 2A/2B, Bigger Hearts R & S English 2 just the first half, so half-speed
Year 3 - your child should be ready to move into Bigger Hearts at this point, and LA/math would look like this:
Bigger Hearts Level 2 Dictation, Bigger's Storytime, Bigger's 3A/3B math, Bigger's R & S English 2 second half, all of left side of plans as is
This kind of plan gets your dc the skills needed to grow into a guide, which is the goal of half-speed pacing. Half-speed pacing is not a long-term solution unless dc have special needs, so working toward giving dc the skills they need to do a full guide along with all of its requirements is the purpose of half-speed. I hope this helps!
In Christ,
Julie